diff --git a/.travis-ci.sh b/.travis-ci.sh
index 544bc189c9b..16696460a66 100755
--- a/.travis-ci.sh
+++ b/.travis-ci.sh
@@ -29,7 +29,7 @@ init-bootstrap () {
     eval $(opam env)
     # extlib is installed, since UChar.cmi causes problems with the search
     # order. See also the removal of uChar and uTF8 in src_ext/jbuild-extlib-src
-    opam install cohttp-lwt-unix ssl cmdliner dose3 cudf.0.9 opam-file-format re extlib dune 'mccs>=1.1+5' --yes
+    opam install ssl cmdliner dose3 cudf.0.9 opam-file-format re extlib dune 'mccs>=1.1+5' --yes
   fi
   rm -f "$OPAMBSROOT"/log/*
 }
@@ -102,7 +102,10 @@ EOF
         tar -xzf ocaml-$OCAML_VERSION.tar.gz
         cd ocaml-$OCAML_VERSION
         if [[ $OPAM_TEST -ne 1 ]] ; then
-          CONFIGURE_SWITCHES="-no-ocamldoc -no-ocamlbuild"
+          CONFIGURE_SWITCHES="-no-ocamldoc"
+          if [[ "$OCAML_VERSION" != "4.02.3" ]] ; then
+            CONFIGURE_SWITCHES="$CONFIGURE_SWITCHES -no-ocamlbuild"
+          fi
         fi
         ./configure --prefix ~/local -no-graph -no-debugger ${CONFIGURE_SWITCHES:-}
         if [[ $OPAM_TEST -eq 1 ]] ; then
@@ -156,6 +159,7 @@ export OCAMLRUNPARAM=b
     make lib-ext
   fi
   make all
+  make man
 
   rm -f ~/local/bin/opam
   make install
@@ -167,10 +171,10 @@ export OCAMLRUNPARAM=b
     done
     # Compile and run opam-rt
     cd ~/build
-    wget https://github.com/ocaml/opam-rt/archive/$TRAVIS_PULL_REQUEST_BRANCH.tar.gz -O opam-rt.tar.gz || \
-    wget https://github.com/ocaml/opam-rt/archive/master.tar.gz -O opam-rt.tar.gz
+    wget https://github.com/ocaml/opam-rt/archive/opam2.0.tar.gz -O opam-rt.tar.gz
     tar -xzf opam-rt.tar.gz
     cd opam-rt-*
+    opam install ./opam-rt.opam --deps-only -y
     make
 
     opam switch default
diff --git a/CHANGES b/CHANGES
index e438db87ab9..0cad99f6bde 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2,6 +2,24 @@ Changes prefixed with "(*)" are potentially breaking to scripts or existing
 repositories (changes that are automatically handled by the format upgrade tools
 are not marked).
 
+2.0.4:
+* Add (rudimentary) error handling to `make man`
+* Sandboxing on MacOS: considering the possibility that TMPDIR in unset
+* display: Fix opam var display
+* pin:
+  * update source of (version) pinned directory
+  * fix `--ignore-pin-depends` with autopin
+  * fix pinnings not installing/upgrading already pinned packages (introduced in 2.0.2)
+* opam clean: Ignore errors trying to remove directories
+* remove wrong mismatching extra-files warning
+* urls: fix hg opam 1.2 url parsing
+* lint: warning error 47 on descr first line
+* dirtrack: fix precise tracking mode
+* system:
+  * lock & signals: don't interrupt at non terminal signals
+  * shell: fix fish manpath setting
+  * git: use git -c diff.noprefix=false diff in case it is defined in user config
+
 2.0.3:
 * Fix manpage remaining $ (OPAMBESTEFFORT)
 * Fix OPAMROOTISOK handling
@@ -552,12 +570,12 @@ are not marked).
 * Improve the syntax of filters
 * Add a `messages` field
 * Add a `--jobs` command line option and add `%{jobs}%` to be used in OPAM files
-* Various improvments in the solver heuristics
+* Various improvements in the solver heuristics
 * By default, turn-on checking of certificates for downloaded dependency archives: use `./configure --disable-certificate-check` to go back to the previous behavior
 * Check the md5sum of downloaded archives when compiling OPAM
 * Improved `opam info` command (more information, non-zero error code when no patterns match)
 * Display OS and OPAM version on internal errors to ease error reporting
-* Fix `opam reinstall` when reinstalling a package wich is a dependency of installed packages (regression introduced in 0.9.5)
+* Fix `opam reinstall` when reinstalling a package which is a dependency of installed packages (regression introduced in 0.9.5)
 * Export and read `OPAMSWITCH` to be able to call OPAM in different switches
 * `opam-client` can now be used in a toplevel
 * `-n` now means `--no-setup` and not `--no-checksums` anymore
@@ -700,7 +718,7 @@ are not marked).
 * improve opam-mk-repo
 * fix `opam search` to be caseless
 * ability to filter some commands (depending on some predicates) in opam file
-* improvments when packages disapear upstream
+* improvements when packages disappear upstream
 * check for ocaml 3.12.1 on configure
 * tell the user to unset some potentially dangerous variables when running opam
 * fix few git backend issues
diff --git a/configure b/configure
index c0aa4fd75ae..eca5c59613c 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for opam 2.0.3.
+# Generated by GNU Autoconf 2.69 for opam 2.0.4.
 #
 #
 # Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
@@ -578,8 +578,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='opam'
 PACKAGE_TARNAME='opam'
-PACKAGE_VERSION='2.0.3'
-PACKAGE_STRING='opam 2.0.3'
+PACKAGE_VERSION='2.0.4'
+PACKAGE_STRING='opam 2.0.4'
 PACKAGE_BUGREPORT=''
 PACKAGE_URL=''
 
@@ -1264,7 +1264,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures opam 2.0.3 to adapt to many kinds of systems.
+\`configure' configures opam 2.0.4 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1326,7 +1326,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of opam 2.0.3:";;
+     short | recursive ) echo "Configuration of opam 2.0.4:";;
    esac
   cat <<\_ACEOF
 
@@ -1429,7 +1429,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-opam configure 2.0.3
+opam configure 2.0.4
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -1524,7 +1524,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by opam $as_me 2.0.3, which was
+It was created by opam $as_me 2.0.4, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -6001,7 +6001,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by opam $as_me 2.0.3, which was
+This file was extended by opam $as_me 2.0.4, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -6054,7 +6054,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-opam config.status 2.0.3
+opam config.status 2.0.4
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index 87ae97f28a8..16e0f0b61a3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,5 +1,5 @@
 dnl The line below must be formatted AC_INIT(opam,VERSION) with no extra spaces
-AC_INIT(opam,2.0.3)
+AC_INIT(opam,2.0.4)
 AC_COPYRIGHT(Copyright 2012-2017 OcamlPro SAS)
 
 AC_CONFIG_MACRO_DIR([m4])
diff --git a/doc/Makefile b/doc/Makefile
index f4f4b5d0c3e..9f00bfd597c 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -33,15 +33,17 @@ all: man html pages
 man:
 	rm -rf man
 	mkdir -p man
-	$(OPAM) $(HELPFMT) > man/opam.1
+	$(OPAM) $(HELPFMT) > man/opam.1 2> man/err
 	for i in $(TOPICS); do\
-	  $(OPAM) $$i $(HELPFMT) > man/opam-$$i.1;\
+	  $(OPAM) $$i $(HELPFMT) > man/opam-$$i.1 2>> man/err ; \
 	done
-	$(OPAM) admin $(HELPFMT) > man/opam-admin.1
+	$(OPAM) admin $(HELPFMT) > man/opam-admin.1 2>> man/err
 	for i in $(TOPICS_ADMIN); do\
-	  $(OPAM) admin $$i $(HELPFMT) > man/opam-admin-$$i.1;\
+	  $(OPAM) admin $$i $(HELPFMT) > man/opam-admin-$$i.1 2>> man/err ; \
 	done
-	$(OPAM_INSTALLER) $(HELPFMT) > man/opam-installer.1
+	$(OPAM_INSTALLER) $(HELPFMT) > man/opam-installer.1 2>> man/err
+# Dune doesn't (yet) support --no-print-directory
+	@if grep -v "^Entering directory '" man/err > man/err2 ; then cat man/err2 ; false ; fi
 
 man-html: man
 	rm -rf man-html
diff --git a/doc/design/depexts-plugins b/doc/design/depexts-plugins
index 3ccbb071fae..2fece2a27a2 100644
--- a/doc/design/depexts-plugins
+++ b/doc/design/depexts-plugins
@@ -67,7 +67,7 @@ cases outlined above:
    or an explanation for the failure, while perform executes the actions (typically
    after user confirmation)
 
-The proposed module interface is purposedly incomplete, as it makes no assumption
+The proposed module interface is intentionally incomplete, as it makes no assumption
 on the way in which plugins are identified, and registered, which is an orthogonal
 issue.
 
diff --git a/doc/design/depopts-and-features b/doc/design/depopts-and-features
index f36b14a6b7c..08c1539b113 100644
--- a/doc/design/depopts-and-features
+++ b/doc/design/depopts-and-features
@@ -75,7 +75,7 @@ but presented in order of increased implementation complexity
         package is scheduled.
 
         The depopts: field is not used at all by the package dependencies
-        resolution phase, and must not be transalted into CUDF.
+        resolution phase, and must not be translated into CUDF.
 
         After the solver returns a solution, packages in this list that are
         present in the system are added with all their dependencies to the
diff --git a/doc/design/provides.md b/doc/design/provides.md
index fa6291a0eee..a62524fe171 100644
--- a/doc/design/provides.md
+++ b/doc/design/provides.md
@@ -35,7 +35,7 @@ versions.
 
 The feature provided can already be encoded without an extra field: given a list
 of packages that `provide` a given name, a package by this name can be added
-with a dependency towards either of those. However, on a repository maintainance
+with a dependency towards either of those. However, on a repository maintenance
 point of view, having to list all the alternatives adds much more burden.
 
 Besides, it's not possible, using pinning or an additional repository, to
diff --git a/doc/pages/External_solvers.md b/doc/pages/External_solvers.md
index 63ce79b7247..dbb8762122b 100644
--- a/doc/pages/External_solvers.md
+++ b/doc/pages/External_solvers.md
@@ -61,7 +61,7 @@ For example, the preference `-removed` tells the solver that among all possible
 These combinators can be combined in a comma separated sequence, that is treated in lexicographic order by the solver.
 
 ### Default preferences for an upgrade
-For example, the preference `-removed,-notuptodate,-changed` tells the solver that after ensuring that removals are minimised, it should look for a solution that minimises also the number of packages wich are not at their latest version, and then reduce the changes to a minimum.
+For example, the preference `-removed,-notuptodate,-changed` tells the solver that after ensuring that removals are minimised, it should look for a solution that minimises also the number of packages which are not at their latest version, and then reduce the changes to a minimum.
 
 This is close to the default preference setting used by `opam` when you perform an update or an upgrade, and in practice it tries to bring _all_ your packages to the latest version available, as far as this does not implies removing too many packages. It can be set using the environment variable `OPAMUPGRADECRITERIA`, or the [`solver-upgrade-criteria:`](Manual.html#configfield-solver-upgrade-criteria) configuration field.
 
@@ -71,7 +71,7 @@ When you request to install a (set of) package(s), in general you do not expect
 ### Specifying preferences for opam
 
 `opam` allows to specify your criteria on the command line, using the `--criteria` option, that will apply only to the current command.
-For example if you are a very conservative user, you might try issueing the following command:
+For example, if you are a very conservative user, you might try issuing the following command:
 ```
 opam install --criteria="-removed,-changed" ...
 ```
diff --git a/doc/pages/Specifying_Solver_Preferences.md b/doc/pages/Specifying_Solver_Preferences.md
index 45f54b10af7..740683545b4 100644
--- a/doc/pages/Specifying_Solver_Preferences.md
+++ b/doc/pages/Specifying_Solver_Preferences.md
@@ -25,7 +25,7 @@ For example, the preference  `-removed`  tells the solver that among all possibl
 These combinators can be combined in a comma separated sequence, that is treated in lexicographic order by the solver.
 
 ### Default preferences for an upgrade
-For example, the preference  `-removed,-notuptodate,-changed`  tells the solver that after ensuring that removals are minimised, it should look for a solution that minimises also the number of packages wich are not at their latest version, and then reduce the changes to a minimum.
+For example, the preference  `-removed,-notuptodate,-changed`  tells the solver that after ensuring that removals are minimised, it should look for a solution that minimises also the number of packages which are not at their latest version, and then reduce the changes to a minimum.
 
 This is the default preference setting used by `opam` when you perform an update or an upgrade, and in practice it tries to bring _all_ your packages to the latest version available, as far as this does not implies removing too many packages. It can be set using the environment variable `OPAMUPGRADECRITERIA`
 
@@ -35,7 +35,7 @@ When you request to install a (set of) package(s), in general you do not expect
 ### Specifying preferences for opam
 
 Recent versions of `opam` allow to specify your criteria on the command line, using the `--criteria` option, that will apply only to the current command.
-For example if you are a very conservative user, you might try issueing the following command:
+For example, if you are a very conservative user, you might try issuing the following command:
 ```
 opam install --criteria="-removed,-changed" ...
 ```
diff --git a/doc/pages/Tricks.md b/doc/pages/Tricks.md
index 500b640ea7b..39639d127ff 100644
--- a/doc/pages/Tricks.md
+++ b/doc/pages/Tricks.md
@@ -103,7 +103,7 @@ to:
   is to use the `conflict-class:` field: add _e.g._ `conflict-class:
   "foo-implementation"` to all versions of both `a` and `b`.
 
-The need to define the virtual package explicitely also ensures that a third
+The need to define the virtual package explicitly also ensures that a third
 package can't inject a new implementation without that being visible in `foo`:
 it would otherwise be a security hole when we deploy end-to-end signing of
 packages.
diff --git a/opam-client.opam b/opam-client.opam
index 15f03e3898e..8065a2141eb 100644
--- a/opam-client.opam
+++ b/opam-client.opam
@@ -1,5 +1,5 @@
 opam-version: "1.2"
-version: "2.0.3"
+version: "2.0.4"
 maintainer: "opam-devel@lists.ocaml.org"
 authors: [
   "Vincent Bernardoff <vb@luminar.eu.org>"
@@ -21,8 +21,8 @@ build: [
   [make "%{name}%.install"]
 ]
 depends: [
-  "opam-state" {= "2.0.3"}
-  "opam-solver" {= "2.0.3"}
+  "opam-state" {= "2.0.4"}
+  "opam-solver" {= "2.0.4"}
   "re" {>= "1.7.2"}
   "cmdliner" {>= "0.9.8"}
   "dune" {build & >= "1.2.1"}
diff --git a/opam-core.opam b/opam-core.opam
index 8fddb378876..22a831d0f83 100644
--- a/opam-core.opam
+++ b/opam-core.opam
@@ -1,5 +1,5 @@
 opam-version: "1.2"
-version: "2.0.3"
+version: "2.0.4"
 maintainer: "opam-devel@lists.ocaml.org"
 authors: [
   "Vincent Bernardoff <vb@luminar.eu.org>"
diff --git a/opam-devel.opam b/opam-devel.opam
index 909fb07b3f1..5be27acfc1f 100644
--- a/opam-devel.opam
+++ b/opam-devel.opam
@@ -1,5 +1,5 @@
 opam-version: "1.2"
-version: "2.0.3"
+version: "2.0.4"
 maintainer: "opam-devel@lists.ocaml.org"
 authors: [
   "Vincent Bernardoff <vb@luminar.eu.org>"
@@ -22,12 +22,12 @@ build: [
 ]
 build-test: [make "tests"]
 depends: [
-  "opam-client" {= "2.0.3"}
+  "opam-client" {= "2.0.4"}
   "cmdliner" {>= "0.9.8"}
   "dune" {build & >= "1.2.1"}
 ]
 post-messages: [
-"The development version of opam has been successfuly compiled into %{lib}%/%{name}%. You should not run it from there, please install the binaries to your PATH, e.g. with
+"The development version of opam has been successfully compiled into %{lib}%/%{name}%. You should not run it from there, please install the binaries to your PATH, e.g. with
     sudo cp %{lib}%/%{name}%/* /usr/local/bin
 
 If you just want to give it a try without altering your current installation, you could use instead:
diff --git a/opam-format.opam b/opam-format.opam
index 9142b89cac4..9772470dd98 100644
--- a/opam-format.opam
+++ b/opam-format.opam
@@ -1,5 +1,5 @@
 opam-version: "1.2"
-version: "2.0.3"
+version: "2.0.4"
 maintainer: "opam-devel@lists.ocaml.org"
 authors: [
   "Vincent Bernardoff <vb@luminar.eu.org>"
@@ -21,7 +21,7 @@ build: [
   [make "%{name}%.install"]
 ]
 depends: [
-  "opam-core" {= "2.0.3"}
+  "opam-core" {= "2.0.4"}
   "opam-file-format" {>= "2.0.0~rc2"}
   "dune" {build & >= "1.2.1"}
 ]
diff --git a/opam-installer.opam b/opam-installer.opam
index 58922d42e77..e07352ccd67 100644
--- a/opam-installer.opam
+++ b/opam-installer.opam
@@ -1,5 +1,5 @@
 opam-version: "1.2"
-version: "2.0.3"
+version: "2.0.4"
 maintainer: "opam-devel@lists.ocaml.org"
 authors: [
   "Vincent Bernardoff <vb@luminar.eu.org>"
@@ -21,7 +21,7 @@ build: [
   [make "%{name}%.install"]
 ]
 depends: [
-  "opam-format" {= "2.0.3"}
+  "opam-format" {= "2.0.4"}
   "cmdliner" {>= "0.9.8"}
   "dune" {build & >= "1.2.1"}
 ]
diff --git a/opam-repository.opam b/opam-repository.opam
index 6c09dc381cf..0122dde5b55 100644
--- a/opam-repository.opam
+++ b/opam-repository.opam
@@ -1,5 +1,5 @@
 opam-version: "1.2"
-version: "2.0.3"
+version: "2.0.4"
 maintainer: "opam-devel@lists.ocaml.org"
 authors: [
   "Vincent Bernardoff <vb@luminar.eu.org>"
@@ -21,7 +21,7 @@ build: [
   [make "%{name}%.install"]
 ]
 depends: [
-  "opam-format" {= "2.0.3"}
+  "opam-format" {= "2.0.4"}
   "dune" {build & >= "1.2.1"}
 ]
 available: ocaml-version >= "4.02.3"
diff --git a/opam-solver.opam b/opam-solver.opam
index 01cbe61357d..a7bef8baf1e 100644
--- a/opam-solver.opam
+++ b/opam-solver.opam
@@ -1,5 +1,5 @@
 opam-version: "1.2"
-version: "2.0.3"
+version: "2.0.4"
 maintainer: "opam-devel@lists.ocaml.org"
 authors: [
   "Vincent Bernardoff <vb@luminar.eu.org>"
@@ -21,7 +21,7 @@ build: [
   [make "%{name}%.install"]
 ]
 depends: [
-  "opam-format" {= "2.0.3"}
+  "opam-format" {= "2.0.4"}
   "mccs" {>= "1.1+9"}
   "dose3" {>= "5"}
   "cudf" {>= "0.7"}
diff --git a/opam-state.opam b/opam-state.opam
index 527b6464b13..ac41ad9e767 100644
--- a/opam-state.opam
+++ b/opam-state.opam
@@ -1,5 +1,5 @@
 opam-version: "1.2"
-version: "2.0.3"
+version: "2.0.4"
 maintainer: "opam-devel@lists.ocaml.org"
 authors: [
   "Vincent Bernardoff <vb@luminar.eu.org>"
@@ -21,7 +21,7 @@ build: [
   [make "%{name}%.install"]
 ]
 depends: [
-  "opam-repository" {= "2.0.3"}
+  "opam-repository" {= "2.0.4"}
   "dune" {build & >= "1.2.1"}
 ]
 available: ocaml-version >= "4.02.3"
diff --git a/shell/bundle.sh b/shell/bundle.sh
index 2dd635605c2..b390a1e077b 100755
--- a/shell/bundle.sh
+++ b/shell/bundle.sh
@@ -2,7 +2,7 @@
 set -ue
 
 OCAMLV=4.04.1
-OPAMV=2.0.3
+OPAMV=2.0.4
 OPAM_REPO=https://opam.ocaml.org/2.0
 DEBUG=
 MAKESELF=
diff --git a/shell/install.sh b/shell/install.sh
index 5325cd440a9..26e3785905a 100755
--- a/shell/install.sh
+++ b/shell/install.sh
@@ -120,7 +120,7 @@ fi
 
 TMP=${TMPDIR:-/tmp}
 
-ARCH=$(uname -m || echo unknwon)
+ARCH=$(uname -m || echo unknown)
 case "$ARCH" in
     x86|i?86) ARCH="i686";;
     x86_64|amd64) ARCH="x86_64";;
@@ -181,7 +181,7 @@ if [ -e "$TMP/$OPAM_BIN" ] && ! check_sha512 || [ ! -e "$TMP/$OPAM_BIN" ]; then
         if check_sha512; then
             echo "## Downloaded."
         else
-            echo "Checksum mismatch, a problem occured during download."
+            echo "Checksum mismatch, a problem occurred during download."
             exit 10
         fi
     fi
diff --git a/src/client/opamAction.ml b/src/client/opamAction.ml
index b5a8cb16ef7..4a2c42bfcaa 100644
--- a/src/client/opamAction.ml
+++ b/src/client/opamAction.ml
@@ -148,8 +148,14 @@ let download_package st nv =
   else
   let dir = OpamSwitchState.source_dir st nv in
   if OpamPackage.Set.mem nv st.pinned &&
-     OpamFilename.exists_dir dir
-  then Done None
+     OpamFilename.exists_dir dir &&
+     OpamStd.Option.Op.(
+       OpamPinned.find_opam_file_in_source nv.name dir >>=
+       OpamFile.OPAM.read_opt >>=
+       OpamFile.OPAM.version_opt)
+     = Some nv.version
+  then
+    Done None
   else
     (OpamUpdate.cleanup_source st
        (OpamPackage.Map.find_opt nv st.installed_opams)
diff --git a/src/client/opamAdminCommand.ml b/src/client/opamAdminCommand.ml
index db100ac32f1..65c8fd420a6 100644
--- a/src/client/opamAdminCommand.ml
+++ b/src/client/opamAdminCommand.ml
@@ -685,7 +685,7 @@ let env_arg =
           comma-separated 'var=value' bindings, when resolving variables. \
           This is used e.g. when computing available packages: if undefined, \
           availability of packages is not taken into account. Note that, \
-          unless overriden, variables like 'root' or 'opam-version' may be \
+          unless overridden, variables like 'root' or 'opam-version' may be \
           taken from the current opam installation. What is defined in \
           $(i,~/.opam/config) is always ignored.")
 
diff --git a/src/client/opamAuxCommands.ml b/src/client/opamAuxCommands.ml
index 39c98e29685..6002864c0bf 100644
--- a/src/client/opamAuxCommands.ml
+++ b/src/client/opamAuxCommands.ml
@@ -400,6 +400,7 @@ let autopin st ?(simulate=false) ?quiet atom_or_local_list =
       OpamStd.Sys.exit_because `Aborted
   in
   let st =
+    if OpamClientConfig.(!r.ignore_pin_depends) then st else
     OpamPackage.Set.fold (fun nv st ->
         OpamPinCommand.handle_pin_depends st nv (OpamSwitchState.opam st nv))
       (OpamPackage.Set.union pins already_pinned_set) st
@@ -491,13 +492,13 @@ let get_compatible_compiler ?repos rt dir =
        (OpamStd.Format.itemize OpamPackage.to_string
           (OpamPackage.Set.elements local_packages));
      if OpamConsole.confirm "Do you want to create an empty switch regardless?"
-     then []
+     then [], false
      else OpamStd.Sys.exit_because `Aborted)
   else
   let compilers = OpamPackage.Set.inter compilers installable in
   try
     [OpamSolution.eq_atom_of_package
-       (OpamPackage.Set.choose_one compilers)]
+       (OpamPackage.Set.choose_one compilers)], true
   with
   | Not_found when not (OpamPackage.Set.is_empty local_packages) ->
     OpamConsole.warning
@@ -507,7 +508,7 @@ let get_compatible_compiler ?repos rt dir =
        OpamConsole.confirm
          "Create the switch with no specific compiler selected, and attempt to \
           continue?"
-    then []
+    then [], false
     else OpamStd.Sys.exit_because `Aborted
  | Failure _ | Not_found ->
    (* Find a matching compiler from the default selection *)
@@ -515,7 +516,7 @@ let get_compatible_compiler ?repos rt dir =
      OpamFile.Config.default_compiler gt.config
    in
    if default_compiler = Empty then
-     (OpamConsole.warning "No compiler selected"; [])
+     (OpamConsole.warning "No compiler selected"; [], false)
    else
    let candidates = OpamFormula.to_dnf default_compiler in
    try
@@ -545,7 +546,7 @@ let get_compatible_compiler ?repos rt dir =
             Some (OpamSolution.eq_atoms_of_packages compiler)
           else None
        )
-       candidates
+       candidates, false
    with Not_found ->
       OpamConsole.warning
         "The default compiler selection: %s\n\
@@ -557,5 +558,5 @@ let get_compatible_compiler ?repos rt dir =
       if OpamConsole.confirm
           "You may also proceed, with no specific compiler selected. \
            Do you want to?"
-      then []
+      then [], false
       else OpamStd.Sys.exit_because `Aborted
diff --git a/src/client/opamAuxCommands.mli b/src/client/opamAuxCommands.mli
index cb3efccbc97..570809bb5f1 100644
--- a/src/client/opamAuxCommands.mli
+++ b/src/client/opamAuxCommands.mli
@@ -21,7 +21,7 @@ open OpamStateTypes
 val copy_files_to_destdir: 'a switch_state -> dirname -> package_set -> unit
 
 (** Removes all files that may have been installed by [copy_files_to_destdir];
-    it's more agressive than [OpamDirTrack.revert] and doesn't check if the
+    it's more aggressive than [OpamDirTrack.revert] and doesn't check if the
     files are current. *)
 val remove_files_from_destdir: 'a switch_state -> dirname -> package_set -> unit
 
@@ -91,4 +91,4 @@ val simulate_autopin:
     warning, and returns the empty list after user confirmation. *)
 val get_compatible_compiler:
   ?repos:repository_name list ->
-  'a repos_state -> dirname -> atom list
+  'a repos_state -> dirname -> atom list * bool
diff --git a/src/client/opamClient.ml b/src/client/opamClient.ml
index 6e3b6355e8d..40965b20de2 100644
--- a/src/client/opamClient.ml
+++ b/src/client/opamClient.ml
@@ -248,7 +248,10 @@ let compute_upgrade_t
        ~upgrade:upgrade_atoms
        ())
 
-let upgrade_t ?strict_upgrade ?auto_install ?ask ?(check=false) ~all atoms t =
+let upgrade_t
+    ?strict_upgrade ?auto_install ?ask ?(check=false) ?(terse=false) ~all
+    atoms t
+  =
   log "UPGRADE %a"
     (slog @@ function [] -> "<all>" | a -> OpamFormula.string_of_atoms a)
     atoms;
@@ -306,6 +309,8 @@ let upgrade_t ?strict_upgrade ?auto_install ?ask ?(check=false) ~all atoms t =
       let notuptodate = latest -- to_check in
       if OpamPackage.Set.is_empty notuptodate then
         OpamConsole.msg "Already up-to-date.\n"
+      else if terse then
+        OpamConsole.msg "No package build needed.\n"
       else
         (let hdmsg = "Everything as up-to-date as possible" in
          let unav = notuptodate -- Lazy.force t.available_packages in
@@ -1262,9 +1267,20 @@ let reinstall t ?(assume_built=false) names =
 module PIN = struct
   open OpamPinCommand
 
-  let post_pin_action st names =
+  let post_pin_action st was_pinned names =
+    let names =
+      OpamPackage.Set.Op.(st.pinned -- was_pinned)
+      |> OpamPackage.names_of_packages
+      |> (fun s ->
+          List.fold_left
+            (fun s p -> OpamPackage.Name.Set.add p s)
+            s names)
+      |> OpamPackage.Name.Set.elements
+    in
     try
-      upgrade_t ~strict_upgrade:false ~auto_install:true ~ask:true ~all:false
+      upgrade_t
+        ~strict_upgrade:false ~auto_install:true ~ask:true ~terse:true
+        ~all:false
        (List.map (fun name -> name, None) names) st
     with e ->
       OpamConsole.note
@@ -1304,13 +1320,7 @@ module PIN = struct
           source_pin st name ?version ~edit (Some (get_upstream st name))
         | `None -> source_pin st name ?version ~edit None
       in
-      if action then
-        let names =
-          OpamPackage.Set.Op.(st.pinned -- pinned)
-          |> OpamPackage.Set.elements
-          |> List.map OpamPackage.name
-        in
-        (OpamConsole.msg "\n"; post_pin_action st names)
+      if action then (OpamConsole.msg "\n"; post_pin_action st pinned [name])
       else st
     with
     | OpamPinCommand.Aborted -> OpamStd.Sys.exit_because `Aborted
@@ -1350,13 +1360,7 @@ module PIN = struct
         OpamConsole.error_and_exit `Not_found
           "Package is not pinned, and no existing version was supplied."
     in
-    if action then
-      let names =
-        OpamPackage.Set.Op.(st.pinned -- pinned)
-        |> OpamPackage.Set.elements
-        |> List.map OpamPackage.name
-      in
-      post_pin_action st names
+    if action then post_pin_action st pinned [name]
     else st
 
   let unpin st ?(action=true) names =
@@ -1372,7 +1376,9 @@ module PIN = struct
             else (nv.name, None) :: acc)
           installed_unpinned []
       in
-      upgrade_t ~strict_upgrade:false ~auto_install:true ~ask:true ~all:false
+      upgrade_t
+        ~strict_upgrade:false ~auto_install:true ~ask:true ~all:false
+        ~terse:true
         atoms st
     else st
 
diff --git a/src/client/opamClient.mli b/src/client/opamClient.mli
index 46ca3dc4a1a..26e25881770 100644
--- a/src/client/opamClient.mli
+++ b/src/client/opamClient.mli
@@ -85,10 +85,12 @@ val update:
 val upgrade:
   rw switch_state -> ?check:bool -> all:bool -> atom list -> rw switch_state
 
-(** Low-level version of [upgrade], bypassing the package name sanitization
-    and dev package update, and offering more control *)
+(** Low-level version of [upgrade], bypassing the package name sanitization and
+   dev package update, and offering more control. [terse] avoids the verbose
+   message when we are at a local maximum, but there are possible upgrades *)
 val upgrade_t:
   ?strict_upgrade:bool -> ?auto_install:bool -> ?ask:bool -> ?check:bool ->
+  ?terse:bool ->
   all:bool -> atom list -> rw switch_state -> rw switch_state
 
 (** Recovers from an inconsistent universe *)
@@ -121,4 +123,9 @@ module PIN: sig
   (** List the current pinned packages. *)
   val list: 'a switch_state -> short:bool -> unit
 
+  (** Runs an install/upgrade on the listed packages if necessary.
+      [post_pin_action st was_pinned names] takes the set of packages pinned
+      beforehand, and a list of newly pinned packages *)
+  val post_pin_action: rw switch_state -> package_set -> name list -> rw switch_state
+
 end
diff --git a/src/client/opamCommands.ml b/src/client/opamCommands.ml
index 1500a4ba5a9..e671209996d 100644
--- a/src/client/opamCommands.ml
+++ b/src/client/opamCommands.ml
@@ -184,7 +184,7 @@ let init =
     `S "ARGUMENTS";
     `S "OPTIONS";
     `S "CONFIGURATION FILE";
-    `P "Any field from the built-in initial configuration can be overriden \
+    `P "Any field from the built-in initial configuration can be overridden \
         through $(i,~/.opamrc), $(i,/etc/opamrc), or a file supplied with \
         $(i,--config). The default configuration for this version of opam \
         can be obtained using $(b,--show-default-opamrc).";
@@ -285,7 +285,7 @@ let init =
   let no_sandboxing =
     mk_flag ["disable-sandboxing"]
       "Use a default configuration with sandboxing disabled (note that this \
-       may be overriden by `opamrc' if $(b,--no-opamrc) is not specified or \
+       may be overridden by `opamrc' if $(b,--no-opamrc) is not specified or \
        $(b,--config) is used). Use this at your own risk, without sandboxing \
        it is possible for a broken package script to delete all your files."
   in
@@ -1564,7 +1564,7 @@ let repository =
      package definitions anymore. With $(b,--all), makes opam forget about \
      these repositories completely.";
     "set-repos", `set_repos, ["NAME..."],
-    "Explicitely selects the list of repositories to look up package \
+    "Explicitly selects the list of repositories to look up package \
      definitions from, in the specified priority order (overriding previous \
      selection and ranks), according to the specified scope.";
     "set-url", `set_url, ["NAME"; "ADDRESS"; "[QUORUM]"; "[FINGERPRINTS]"],
@@ -2040,7 +2040,7 @@ let switch =
       match packages, compiler_opt, OpamSwitch.is_external switch with
       | None, None, false ->
         OpamSwitchCommand.guess_compiler_package ?repos rt
-          (OpamSwitch.to_string switch)
+          (OpamSwitch.to_string switch), false
       | None, None, true ->
         OpamAuxCommands.get_compatible_compiler ?repos rt
           (OpamFilename.dirname_dir
@@ -2049,7 +2049,7 @@ let switch =
         OpamStd.Option.Op.(
           ((compiler_opt >>|
             OpamSwitchCommand.guess_compiler_package ?repos rt) +! []) @
-          packages +! [])
+          packages +! []), false
     in
     let param_compiler = function
       | [] -> None
@@ -2109,7 +2109,7 @@ let switch =
       OpamGlobalState.with_ `Lock_write @@ fun gt ->
       let repos, rt = get_repos_rt gt repos in
       let switch = OpamSwitch.of_string switch_arg in
-      let packages =
+      let packages, local_compiler =
         compiler_packages rt ?repos switch (param_compiler params)
       in
       let _gt, st =
@@ -2117,10 +2117,12 @@ let switch =
           ?synopsis:descr ?repos
           ~update_config:(not no_switch)
           ~packages
+          ~local_compiler
           switch
       in
       let st =
-        if not no_install && not empty && OpamSwitch.is_external switch then
+        if not no_install && not empty &&
+           OpamSwitch.is_external switch && not local_compiler then
           let st, atoms =
             OpamAuxCommands.autopin st ~simulate:deps_only ~quiet:true
               [`Dirname (OpamFilename.Dir.of_string switch_arg)]
@@ -2564,26 +2566,18 @@ let pin ?(unpin_only=false) () =
                      OpamPath.Switch.Overlay.tmp_opam
                        st.switch_global.root st.switch name
                    in
-                   if not (OpamFilename.exists (OpamFile.filename opam_localf)) then
-                     OpamFile.OPAM.write opam_localf opam) opam_opt;
-               try OpamPinCommand.source_pin st name ~edit (Some url)
-               with OpamPinCommand.Aborted -> OpamStd.Sys.exit_because `Aborted
-                  | OpamPinCommand.Nothing_to_do -> st)
+                   if not (OpamFilename.exists (OpamFile.filename opam_localf))
+                   then OpamFile.OPAM.write opam_localf opam)
+                 opam_opt;
+               try OpamPinCommand.source_pin st name ~edit (Some url) with
+               | OpamPinCommand.Aborted -> OpamStd.Sys.exit_because `Aborted
+               | OpamPinCommand.Nothing_to_do -> st)
              st names
          in
-         (* names are in newly pinned packages *)
-         let atoms =
-           OpamPackage.Set.Op.(st.pinned -- pinned)
-           |> OpamPackage.Set.elements
-           |> List.map (fun p -> (OpamPackage.name p, None))
-         in
          if action then
-           let _st =
-             OpamClient.upgrade_t
-               ~strict_upgrade:false ~auto_install:true ~ask:true ~all:false
-               atoms st
-           in
-           `Ok ()
+           (ignore @@
+            OpamClient.PIN.post_pin_action st pinned (List.map fst names);
+            `Ok ())
          else `Ok ())
     | Some `add, [n; target] | Some `default n, [target] ->
       (match (fst package) n with
@@ -2928,14 +2922,16 @@ let clean =
         OpamConsole.msg "rm -rf \"%s\"/*\n"
           (OpamFilename.Dir.to_string d)
       else
-        OpamFilename.cleandir d
+      try OpamFilename.cleandir d
+      with OpamSystem.Internal_error msg -> OpamConsole.warning "Error ignored: %s" msg
     in
     let rmdir d =
       if dry_run then
         OpamConsole.msg "rm -rf \"%s\"\n"
           (OpamFilename.Dir.to_string d)
       else
-        OpamFilename.rmdir d
+      try OpamFilename.rmdir d
+      with OpamSystem.Internal_error msg -> OpamConsole.warning "Error ignored: %s" msg
     in
     let switches =
       if all_switches then OpamGlobalState.switches gt
diff --git a/src/client/opamConfigCommand.ml b/src/client/opamConfigCommand.ml
index 4937cde29a6..4cb579c7b94 100644
--- a/src/client/opamConfigCommand.ml
+++ b/src/client/opamConfigCommand.ml
@@ -29,10 +29,25 @@ let help t =
       all_global_vars
       (OpamVariable.Map.map snd t.switch_global.global_variables)
   in
-  List.map (fun (var, doc) -> [
+  let env = OpamPackageVar.resolve t in
+  List.map (fun (var, doc) ->
+      let content =
+        OpamFilter.ident_string env ~default:"" ([],var,None)
+      in
+      let doc =
+        if doc = OpamGlobalState.inferred_from_system then
+          match OpamStd.Option.Op.(
+              OpamVariable.Map.find_opt var t.switch_global.global_variables
+              >>| fst
+              >>= Lazy.force) with
+          | Some c when (OpamVariable.string_of_variable_contents c) <> content ->
+            "Set through local opam config or env"
+          | _ -> doc
+        else doc
+      in
+      [
         OpamVariable.to_string var % `bold;
-        OpamFilter.ident_string (OpamPackageVar.resolve t) ~default:""
-          ([],var,None) % `blue;
+        content % `blue;
         "#"; doc
       ])
     (OpamVariable.Map.bindings all_global_vars) |>
@@ -159,6 +174,17 @@ let rec print_fish_env env =
               (OpamStd.Env.escape_single_quotes ~using_backslashes:true v))
          v)
   in
+  (* set manpath if and only if fish version >= 2.7 *)
+  let manpath_cmd v =
+    OpamConsole.msg "%s" (
+      (* test for existence of `argparse` builtin, introduced in fish 2.7 .
+       * use `grep' instead of `builtin string match' so that old fish versions do not
+       *     produce unwanted error messages on stderr.
+       * use `grep' inside a `/bin/sh' fragment so that nothing is written to stdout or
+       *     stderr if `grep' does not exist. *)
+      "builtin -n | /bin/sh -c 'grep -q \\'^argparse$\\'' 1>/dev/null 2>/dev/null; and "
+    ) ;
+    set_arr_cmd "MANPATH" v in
   match env with
   | [] -> ()
   | (k, v, _) :: r ->
@@ -170,8 +196,7 @@ let rec print_fish_env env =
           * opamState.ml for details *)
          set_arr_cmd k v
        | "MANPATH" ->
-         if OpamStd.Env.getopt k <> None then
-           set_arr_cmd k v
+         manpath_cmd v
        | _ ->
          OpamConsole.msg "set -gx %s '%s';\n"
            k (OpamStd.Env.escape_single_quotes ~using_backslashes:true v));
@@ -315,32 +340,35 @@ let set_global var value =
   OpamGlobalState.write { gt with config }
 
 let variable gt v =
-  match OpamPackageVar.resolve_global gt v with
-  | Some c ->
-    OpamConsole.msg "%s\n" (OpamVariable.string_of_variable_contents c)
-  | None ->
+  let raw_switch_content =
     match OpamStateConfig.get_switch_opt () with
-    | None ->
-      OpamConsole.error_and_exit `Not_found
-        "Variable %s not found"
-        (OpamVariable.Full.to_string v)
     | Some switch ->
       let switch_config =
         OpamFile.Switch_config.safe_read
           (OpamPath.Switch.switch_config gt.root switch)
       in
-      match OpamPackageVar.resolve_switch_raw gt switch switch_config v with
-      | Some c ->
-        OpamConsole.msg "%s\n" (OpamVariable.string_of_variable_contents c)
-      | None ->
-        OpamSwitchState.with_ `Lock_none gt @@ fun st ->
-        match OpamPackageVar.resolve st v with
-        | Some c ->
-          OpamConsole.msg "%s\n" (OpamVariable.string_of_variable_contents c)
-        | None ->
-          OpamConsole.error_and_exit `Not_found
-            "Variable %s not found"
-            (OpamVariable.Full.to_string v)
+      OpamPackageVar.resolve_switch_raw gt switch switch_config v
+    | None -> None
+  in
+  let switch_content =
+    match raw_switch_content with
+    | None when not (OpamVariable.Full.is_global v) ->
+      OpamSwitchState.with_ `Lock_none gt @@ fun st ->
+      OpamPackageVar.resolve st v
+    | rsc -> rsc
+  in
+  let content =
+    match switch_content with
+    | Some _ as some -> some
+    | None -> OpamPackageVar.resolve_global gt v
+  in
+  match content with
+  | Some c -> OpamConsole.msg "%s\n" (OpamVariable.string_of_variable_contents c)
+  | None ->
+    OpamConsole.error_and_exit `Not_found
+      "Variable %s not found"
+      (OpamVariable.Full.to_string v)
+
 
 let exec gt ?set_opamroot ?set_opamswitch ~inplace_path command =
   log "config-exec command=%a" (slog (String.concat " ")) command;
diff --git a/src/client/opamInitDefaults.mli b/src/client/opamInitDefaults.mli
index 06419db1031..36843f49047 100644
--- a/src/client/opamInitDefaults.mli
+++ b/src/client/opamInitDefaults.mli
@@ -9,7 +9,7 @@
 (**************************************************************************)
 
 (** This module defines a few defaults, used at 'opam init', that bind opam to
-    its default OCaml repository at https://opam.ocaml.org. All can be overriden
+    its default OCaml repository at https://opam.ocaml.org. All can be overridden
     through the init command flags or an init config file. *)
 
 open OpamTypes
diff --git a/src/client/opamSwitchCommand.ml b/src/client/opamSwitchCommand.ml
index 8b5bdc8dbc0..8b1a37fe8a4 100644
--- a/src/client/opamSwitchCommand.ml
+++ b/src/client/opamSwitchCommand.ml
@@ -269,7 +269,7 @@ let install_compiler_packages t atoms =
   OpamSolution.check_solution ~quiet:OpamClientConfig.(not !r.show) t result;
   t
 
-let install gt ?rt ?synopsis ?repos ~update_config ~packages switch =
+let install gt ?rt ?synopsis ?repos ~update_config ~packages ?(local_compiler=false) switch =
   let update_config = update_config && not (OpamSwitch.is_external switch) in
   let old_switch_opt = OpamFile.Config.switch gt.config in
   let comp_dir = OpamPath.Switch.root gt.root switch in
@@ -311,6 +311,13 @@ let install gt ?rt ?synopsis ?repos ~update_config ~packages switch =
       in
       { st with switch; available_packages }
   in
+  let st =
+    if OpamSwitch.is_external switch && local_compiler then
+      OpamAuxCommands.autopin st ~quiet:true
+        [`Dirname (OpamFilename.Dir.of_string (OpamSwitch.to_string switch))]
+      |> fst
+    else st
+  in
   let packages =
     try OpamSolution.sanitize_atom_list st packages
     with e ->
diff --git a/src/client/opamSwitchCommand.mli b/src/client/opamSwitchCommand.mli
index c7804e97f1a..0b25b142571 100644
--- a/src/client/opamSwitchCommand.mli
+++ b/src/client/opamSwitchCommand.mli
@@ -24,7 +24,9 @@ val install:
   ?synopsis:string ->
   ?repos:repository_name list ->
   update_config:bool ->
-  packages:atom conjunction -> switch ->
+  packages:atom conjunction -> 
+  ?local_compiler:bool ->
+  switch ->
   unlocked global_state * rw switch_state
 
 (** Install a compiler's base packages *)
diff --git a/src/core/opamDirTrack.ml b/src/core/opamDirTrack.ml
index 9eed72c2d6f..45ed3a0ac88 100644
--- a/src/core/opamDirTrack.ml
+++ b/src/core/opamDirTrack.ml
@@ -60,7 +60,7 @@ let cached_digest =
   fun f size mtime ->
     try
       let csize, cmtime, digest = Hashtbl.find item_cache f in
-      if csize = size || mtime = cmtime then digest
+      if csize = size || mtime = cmtime then Digest.to_hex digest
       else raise Not_found
     with Not_found ->
       let digest = Digest.file f in
diff --git a/src/core/opamProcess.ml b/src/core/opamProcess.ml
index 42ff6ad61b5..9475bfdbdbe 100644
--- a/src/core/opamProcess.ml
+++ b/src/core/opamProcess.ml
@@ -131,7 +131,7 @@ let string_of_info ?(color=`yellow) info =
     [cmd] with arguments [args]. If [stdout_file] or [stderr_file] are
     set, the channels are redirected to the corresponding files.  The
     outputs are discarded is [verbose] is set to false. The current
-    environment can also be overriden if [env] is set. The environment
+    environment can also be overridden if [env] is set. The environment
     which is used to run the process is recorded into [env_file] (if
     set). *)
 let create ?info_file ?env_file ?(allow_stdin=true) ?stdout_file ?stderr_file ?env ?(metadata=[]) ?dir
diff --git a/src/core/opamStd.mli b/src/core/opamStd.mli
index 4a623d03088..74129dfbab8 100644
--- a/src/core/opamStd.mli
+++ b/src/core/opamStd.mli
@@ -236,13 +236,13 @@ module String : sig
 
   (** {4 Transformations} *)
 
-  (** Cut a string at the first occurence of the given char *)
+  (** Cut a string at the first occurrence of the given char *)
   val cut_at: string -> char -> (string * string) option
 
   (** Same as [cut_at], but starts from the right *)
   val rcut_at: string -> char -> (string * string) option
 
-  (** Split a string at occurences of a given characters. Empty strings are
+  (** Split a string at occurrences of a given characters. Empty strings are
       skipped. *)
   val split: string -> char -> string list
 
@@ -419,7 +419,7 @@ module Sys : sig
   (** Indicates intention to exit the program with given exit code *)
   exception Exit of int
 
-  (** Indicates intention to exec() the given command (paramters as per
+  (** Indicates intention to exec() the given command (parameters as per
       [Unix.execvpe]), after proper finalisations. It's the responsibility of
       the main function to catch this, call [exec_at_exit], and
       [Unix.execvpe]. *)
diff --git a/src/core/opamSystem.ml b/src/core/opamSystem.ml
index 90b68959826..81133b3e1a0 100644
--- a/src/core/opamSystem.ml
+++ b/src/core/opamSystem.ml
@@ -817,12 +817,18 @@ let rec flock_update
            Unix.(lockf fd F_ULOCK 0);
          Unix.lockf fd (unix_lock_op ~dontblock:true flag) 0
        with Unix.Unix_error (Unix.EAGAIN,_,_) ->
-         if dontblock then raise Locked;
+         if dontblock then
+           OpamConsole.error_and_exit `Locked
+             "Another process has locked %s and non blocking mode enabled"
+             file;
          OpamConsole.formatted_msg
            "Another process has locked %s, waiting (%s to abort)... "
            file (if Sys.win32 then "CTRL+C" else "C-c");
-         (try Unix.lockf fd (unix_lock_op ~dontblock:false flag) 0;
-          with Sys.Break as e -> OpamConsole.msg "\n"; raise e);
+         let rec lock_w_ignore_sig () =
+           try Unix.lockf fd (unix_lock_op ~dontblock:false flag) 0;
+           with Sys.Break as e -> (OpamConsole.msg "\n"; raise e)
+              | Unix.Unix_error (Unix.EINTR,_,_) -> lock_w_ignore_sig ()
+         in lock_w_ignore_sig ();
          OpamConsole.msg "lock acquired.\n");
     lock.kind <- (flag :> lock_flag)
   | _ -> assert false
diff --git a/src/core/opamUrl.ml b/src/core/opamUrl.ml
index d2e2115dfa0..d895df48ea3 100644
--- a/src/core/opamUrl.ml
+++ b/src/core/opamUrl.ml
@@ -36,7 +36,7 @@ let split_url =
         opt @@ seq [
           (* Backend *)
           opt @@ seq [ group @@ rep @@ diff any (set "+:");
-                       char '+' ];
+                       alt [ char '+'; str "://"] ];
           (* Protocol *)
           group @@ rep @@ diff any (char ':');
           (* Separator *)
diff --git a/src/core/opamVersionCompare.ml b/src/core/opamVersionCompare.ml
index 016e179bc59..e11f4f530d3 100644
--- a/src/core/opamVersionCompare.ml
+++ b/src/core/opamVersionCompare.ml
@@ -75,7 +75,7 @@ let skip_zeros x xi xl = skip_while_from xi (fun c -> c = '0') x xl;;
 
 (* compare versions chunks, that is parts of version strings that are
  * epoch, upstream version, or revisision. Alternates string comparison
- * and numerical comaprison.  *)
+ * and numerical comparison.  *)
 let compare_chunks x y =
   (* x and y may be empty *)
   let xl = String.length x
diff --git a/src/format/opamVariable.ml b/src/format/opamVariable.ml
index 832ad00aab2..9cc2fcd5321 100644
--- a/src/format/opamVariable.ml
+++ b/src/format/opamVariable.ml
@@ -57,7 +57,7 @@ module Full = struct
     in
     { scope; variable }
 
-  (* Read the variables overriden through the environment *)
+  (* Read the variables overridden through the environment *)
   let read_from_env v =
     let var_str = to_string (variable v) in
     let undash = OpamStd.String.map (function '-' -> '_' | c -> c) in
diff --git a/src/repository/opamGit.ml b/src/repository/opamGit.ml
index 8ea157b5c11..7c6635504d8 100644
--- a/src/repository/opamGit.ml
+++ b/src/repository/opamGit.ml
@@ -33,6 +33,8 @@ module VCS : OpamVCS.VCS = struct
       git repo_root [ "init" ];
       (* Enforce this option, it can break our use of git if set *)
       git repo_root [ "config" ; "--local" ; "fetch.prune"; "false"];
+      (* We reset diff.noprefix to ensure we get a `-p1` patch and avoid <https://github.com/ocaml/opam/issues/3627>. *)
+      git repo_root [ "config" ; "--local" ; "diff.noprefix"; "false"];
       (* Document the remote for user-friendliness (we don't use it) *)
       git repo_root [ "remote"; "add"; "origin"; OpamUrl.base_url repo_url ];
     ] @@+ function
@@ -156,7 +158,8 @@ module VCS : OpamVCS.VCS = struct
     (* Git diff is to the working dir, but doesn't work properly for
        unregistered directories. *)
     OpamSystem.raise_on_process_error r;
-    git repo_root ~stdout:patch_file [ "diff" ; "--no-ext-diff" ; "-R" ; "-p" ; rref; "--" ]
+    (* We also reset diff.noprefix here to handle already existing repo. *)
+    git repo_root ~stdout:patch_file [ "-c" ; "diff.noprefix=false" ; "diff" ; "--no-ext-diff" ; "-R" ; "-p" ; rref; "--" ]
     @@> fun r ->
     if not (OpamProcess.check_success_and_cleanup r) then
       (finalise ();
diff --git a/src/repository/opamRepositoryBackend.mli b/src/repository/opamRepositoryBackend.mli
index c299f903f41..9dc7b3e8792 100644
--- a/src/repository/opamRepositoryBackend.mli
+++ b/src/repository/opamRepositoryBackend.mli
@@ -69,7 +69,7 @@ module type S = sig
   val revision: dirname -> version option OpamProcess.job
 
   (** Like [pull_url], except for locally-bound version control backends, where
-      it should get the latest, uncommited source. *)
+      it should get the latest, uncommitted source. *)
   val sync_dirty:
     dirname -> url -> filename option download OpamProcess.job
 
@@ -90,7 +90,7 @@ val local: dirname -> repository
     one [expected]. *)
 val check_digest: filename -> OpamHash.t option -> bool
 
-(** Adds a label to the given job, for the correspondig repository name and
+(** Adds a label to the given job, for the corresponding repository name and
     action *)
 val job_text:
   repository_name -> string -> 'a OpamProcess.job -> 'a OpamProcess.job
diff --git a/src/solver/opamCudf.ml b/src/solver/opamCudf.ml
index af72104fb41..e07ff546f55 100644
--- a/src/solver/opamCudf.ml
+++ b/src/solver/opamCudf.ml
@@ -122,7 +122,7 @@ module Graph = struct
       let strong_deps, weak_deps =
         (* strong deps are mandatory (constraint appearing in the top
            conjunction)
-           weak deps correspond to optional occurences of a package, as part of
+           weak deps correspond to optional occurrences of a package, as part of
            a disjunction: e.g. in (A>=4 & (B | A<5)), A>=4 is strong, and the
            other two are weak. In the end we want to retain B and A>=4. *)
         List.fold_left (fun (strong_deps, weak_deps) l ->
diff --git a/src/solver/opamCudf.mli b/src/solver/opamCudf.mli
index 7d94af8e6b8..cb8158dfff8 100644
--- a/src/solver/opamCudf.mli
+++ b/src/solver/opamCudf.mli
@@ -143,7 +143,7 @@ val remove: Cudf.universe -> Cudf_types.pkgname -> Cudf_types.constr -> Cudf.uni
 val uninstall_all: Cudf.universe -> Cudf.universe
 
 (** Install a package in the universe. We don't care about any
-    invariant here (eg. the resulting universe can have mutliple
+    invariant here (eg. the resulting universe can have multiple
     versions of the same package installed). *)
 val install: Cudf.universe -> Cudf.package -> Cudf.universe
 
diff --git a/src/state/opamFileTools.ml b/src/state/opamFileTools.ml
index 4b99a2848ab..b68b7021ace 100644
--- a/src/state/opamFileTools.ml
+++ b/src/state/opamFileTools.ml
@@ -497,7 +497,8 @@ let lint ?check_extra_files t =
        (t.install <> [] || t.remove <> [] || t.url <> None ||
         t.extra_sources <> []));
     cond 47 `Warning
-      "Synopsis should start with a capital and not end with a dot"
+      "Synopsis (or description first line) should start with a capital and \
+       not end with a dot"
       (let valid_re =
          Re.(compile (seq [bos; diff any (alt [blank; lower]); rep any;
                            diff any (alt [blank; char '.']); eos]))
@@ -845,7 +846,8 @@ let add_aux_files ?dir ~files_subdir_hashes opam =
           (OpamFilename.Dir.to_string dir);
         opam
       | Some oef, Some ef ->
-        if oef <> ef then
+        let sort = List.sort (fun (b, _) (b', _) -> compare b b') in
+        if sort oef <> sort ef then
           log "Mismatching extra-files at %s"
             (OpamFilename.Dir.to_string dir);
         opam
diff --git a/src/state/opamGlobalState.ml b/src/state/opamGlobalState.ml
index 92aa9bca2a7..25815cd53b9 100644
--- a/src/state/opamGlobalState.ml
+++ b/src/state/opamGlobalState.ml
@@ -34,6 +34,8 @@ let load_config global_lock root =
   OpamFormatUpgrade.as_necessary global_lock root config;
   config
 
+let inferred_from_system = "Inferred from system"
+
 let load lock_kind =
   let root = OpamStateConfig.(!r.root_dir) in
   log "LOAD-GLOBAL-STATE @ %a" (slog OpamFilename.Dir.to_string) root;
@@ -64,7 +66,9 @@ let load lock_kind =
     List.fold_left (fun acc (v,value) ->
         OpamVariable.Map.add v
           (lazy (Some (OpamStd.Option.default (S "unknown") (Lazy.force value))),
-           "Inferred from system")
+          (* Careful on changing it, it is used to determine user defined
+             variables on `config report`. See [OpamConfigCommand.help]. *)
+           inferred_from_system)
           acc)
       OpamVariable.Map.empty
       (OpamSysPoll.variables)
diff --git a/src/state/opamGlobalState.mli b/src/state/opamGlobalState.mli
index 4a298d8f0e0..013dedd44b4 100644
--- a/src/state/opamGlobalState.mli
+++ b/src/state/opamGlobalState.mli
@@ -39,7 +39,7 @@ val switch_exists: 'a global_state -> switch -> bool
 val installed_versions: 'a global_state -> name -> switch list package_map
 
 (** Default list of repositories to get packages from, ordered by decreasing
-    priority. This can be overriden by switch-specific selections, and does not
+    priority. This can be overridden by switch-specific selections, and does not
     have to include all configured repositories. *)
 val repos_list: 'a global_state -> repository_name list
 
@@ -60,3 +60,6 @@ val write: rw global_state -> unit
     registered if it is set and exists, and removing any non-existing switches.
     Writes back to disk if possible (ie lock is available) *)
 val fix_switch_list: 'a global_state -> 'a global_state
+
+(** Description used for system inferred variables *)
+val inferred_from_system: string
diff --git a/src/state/opamStateTypes.mli b/src/state/opamStateTypes.mli
index c00cebc6921..0e64378157a 100644
--- a/src/state/opamStateTypes.mli
+++ b/src/state/opamStateTypes.mli
@@ -54,7 +54,7 @@ type +'lock global_state = {
   config: OpamFile.Config.t;
   (** The main configuration file. A note of caution: this corresponds to the
       configuration as loaded from the file: to get the current options, which
-      may be overriden through the command-line or environment, see
+      may be overridden through the command-line or environment, see
       OpamStateConfig *)
 
   global_variables:
diff --git a/src/state/opamUpdate.mli b/src/state/opamUpdate.mli
index 477b9c5a406..f384f711fe0 100644
--- a/src/state/opamUpdate.mli
+++ b/src/state/opamUpdate.mli
@@ -47,7 +47,7 @@ val dev_packages:
 
 (** Updates a single dev or pinned package from its upstream. If [working_dir]
     is set, and the package is bound to a local, version-controlled dir, use the
-    working dir state instead of what has been commited to version control.
+    working dir state instead of what has been committed to version control.
 
     Returns true if changed, false otherwise, and a switch_state update
     function, applying possible changes in packages metadata *)
diff --git a/src/state/shellscripts/sandbox_exec.sh b/src/state/shellscripts/sandbox_exec.sh
index 752be7530c9..4926239a4fd 100644
--- a/src/state/shellscripts/sandbox_exec.sh
+++ b/src/state/shellscripts/sandbox_exec.sh
@@ -13,7 +13,20 @@ add_mounts() {
     esac
 }
 
-add_mounts rw "${TMPDIR:-/tmp}"
+if [ -z ${TMPDIR+x} ]; then
+  # If $TMPDIR is not set, some applications use /tmp, so
+  # /tmp must be made readable/writable
+  add_mounts rw /tmp
+  # However, others applications obtain the per-user temporary
+  # directory differently; the latter should be made readable/writable
+  # too and getconf seems to be a robust way to get it
+  if [ -z /usr/bin/getconf ]; then
+    TMP=`getconf DARWIN_USER_TEMP_DIR`
+    add_mounts rw $TMP
+  fi
+else
+  add_mounts rw $TMPDIR
+fi
 
 # C compilers using `ccache` will write to a shared cache directory
 # that remain writeable. ccache seems widespread in some Fedora systems.
diff --git a/tests/README.unittest b/tests/README.unittest
index 57efc1593ee..79bf9fc0496 100644
--- a/tests/README.unittest
+++ b/tests/README.unittest
@@ -9,7 +9,7 @@
 
       ./init-repo.sh -i
 
-* load a inital scenario (this command can be invoked multiple times): 
+* load an initial scenario (this command can be invoked multiple times):
 
       ./init-repo.sh -s 1
       ./init-repo.sh -s 2