gfortran breaks parallel build

[vbraun]

gfortran overwrites compiler parts non-atomically; This breaks parallel compilation:

[gfortran-7.2.0] /bin/sh ../../src/gcc/../mkinstalldirs /Users/buildslave-sage/slave/sage_git/build/local/libexec/gcc/x86_64-apple-darwin17.4.0/7.2.0/plugin
[gfortran-7.2.0] mkdir /Users/buildslave-sage/slave/sage_git/build/local/libexec/gcc/x86_64-apple-darwin17.4.0/7.2.0/plugin
[gfortran-7.2.0] /usr/bin/install -c gengtype /Users/buildslave-sage/slave/sage_git/build/local/libexec/gcc/x86_64-apple-darwin17.4.0/7.2.0/plugin/gengtype
[gfortran-7.2.0] for file in gnat1 brig1 cc1 cc1plus f951 go1  lto1 cc1obj cc1objplus; do \
[gfortran-7.2.0]          if [ -f $file ] ; then \
[gfortran-7.2.0]            rm -f /Users/buildslave-sage/slave/sage_git/build/local/libexec/gcc/x86_64-apple-darwin17.4.0/7.2.0/$file; \
[gfortran-7.2.0]            /usr/bin/install -c $file /Users/buildslave-sage/slave/sage_git/build/local/libexec/gcc/x86_64-apple-darwin17.4.0/7.2.0/$file; \
[gfortran-7.2.0]          else true; \
[gfortran-7.2.0]          fi; \
[gfortran-7.2.0]        done
[flint-2.5.2.p2] gcc: error trying to exec 'cc1': execvp: No such file or directory
[flint-2.5.2.p2] make[4]: *** [../build/fmpq_poly/test/t-scalar_mul_si] Error 1
[flint-2.5.2.p2] gcc -fno-common -ansi -pedantic -Wall -O2 -funroll-loops -g -mpopcnt  -I/Users/buildslave-sage/slave/sage_git/build/local/var/tmp/sage/build/flint-2.5.2.p2/src -I/Users/buildslave-sage/slave/sage_git/build/local/include -I/Users/buildslave-sage/slave/sage_git/build/local/include -I/Users/buildslave-sage/slave/sage_git/build/local/include test/t-scalar_mul_ui.c ../build/fmpq_poly/../../test_helpers.o -o ../build/fmpq_poly/test/t-scalar_mul_ui -L/Users/buildslave-sage/slave/sage_git/build/local/var/tmp/sage/build/flint-2.5.2.p2/src -L/Users/buildslave-sage/slave/sage_git/build/local/lib -L/Users/buildslave-sage/slave/sage_git/build/local/lib -L/Users/buildslave-sage/slave/sage_git/build/local/lib -lflint -lmpfr -lgmp -lm -lntl -lpthread  -MMD -MP -MF ../build/fmpq_poly/test/t-scalar_mul_ui.d -MT "../build/fmpq_poly/test/t-scalar_mul_ui" -MT "../build/fmpq_poly/test/t-scalar_mul_ui.d"

CC: @embray

Component: build

Keywords: random_fail

Author: Jeroen Demeyer

Branch/Commit: 9d14972

Reviewer: Erik Bray

Issue created by migration from https://trac.sagemath.org/ticket/25001

[jdemeyer]

comment:1

Why is gfortran installing gcc in the first place?

[kiwifb]

comment:2

Because you cannot build gfortran without a minimal gcc at this stage. There is a section at the end of spkg-install that renames it so it is not in the way. Patching to avoid install is hard.

[jdemeyer]

comment:3

Replying to @kiwifb:

Because you cannot build gfortran without a minimal gcc at this stage.

Building, I understand. But installing?

[kiwifb]

comment:4

Replying to @jdemeyer:

Replying to @kiwifb:

Because you cannot build gfortran without a minimal gcc at this stage.

Building, I understand. But installing?

I know what you mean but as far as I know you cannot build it without it being an install target. If you know some more configure/install options feel free to enlighten me. Otherwise this is a perfect scenario for Erik's work on staging the install rather than installing directly on the system. You could fix something like that in the staging area before merging the install on the system.

[kiwifb]

comment:5

There is a hack we could use, configure with one of --program-prefix or --program-suffix and then link the resulting gfortran binary to the expected name. Says we pass --program-prefix=sage and then we will have sage-gcc, sage-gfortran and so on installed. As the last step we create a link gfortran to sage-gfortran and since sage-{gcc,g++} is not an expected name for other configure scripts, we should be safe.

[vbraun]

comment:6

Or maybe just not compile other stuff until gfortran is complete, like gcc

[jdemeyer]

comment:7

Replying to @kiwifb:

Otherwise this is a perfect scenario for Erik's work on staging the install rather than installing directly on the system.

+1

[jdemeyer]

comment:8

I'll try the staged install, just to see whether it might work.

[jdemeyer]

Branch: u/jdemeyer/gfortran_breaks_parallel_build

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

330e618	Introduce SAGE_DESTDIR_LOCAL variable
04f992c	Don't install gcc as part of gfortran

[sagetrac-git]

Commit: 04f992c

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

9d14972

Don't install gcc as part of gfortran

[sagetrac-git]

Changed commit from 04f992c to 9d14972

[jdemeyer]

Author: Jeroen Demeyer

[kiwifb]

comment:13

If the bits in sage-spkg do their jobs as expected then it looks good to me.

[embray]

Reviewer: Erik Bray

[vbraun]

Changed branch from u/jdemeyer/gfortran_breaks_parallel_build to 9d14972