Add deprecation warnings to Nix integration

https://cabal.readthedocs.io/en/latest/nix-integration.html
haskell · Sep 3, 2023 · 4e8a3f1 · 4e8a3f1
1 parent 30bb110
commit 4e8a3f1
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Showing 3 changed files with 16 additions and 4 deletions.
diff --git a/cabal-install/src/Distribution/Client/Nix.hs b/cabal-install/src/Distribution/Client/Nix.hs
@@ -47,7 +47,7 @@ import Distribution.Simple.Program
   , simpleProgram
   )
 import Distribution.Simple.Setup (fromFlagOrDefault)
-import Distribution.Simple.Utils (debug, existsAndIsMoreRecentThan)
+import Distribution.Simple.Utils (debug, existsAndIsMoreRecentThan, warn)
 
 import Distribution.Client.Config (SavedConfig (..))
 import Distribution.Client.GlobalFlags (GlobalFlags (..))
@@ -144,6 +144,9 @@ nixShell verb dist globalFlags config go = do
       findNixExpr globalFlags config >>= \case
         Nothing -> go
         Just shellNix -> do
+          -- Nix integration never worked with cabal-install v2 commands ...
+          warn verb "Nix integration has been deprecated and will be removed in a future release. You can learn more about it here: https://cabal.readthedocs.io/en/latest/nix-integration.html"
+
           let prog = simpleProgram "nix-shell"
           progdb <- configureOneProgram verb prog
 

diff --git a/cabal-install/src/Distribution/Client/Setup.hs b/cabal-install/src/Distribution/Client/Setup.hs
@@ -502,17 +502,17 @@ globalCommand commands =
               )
               ""
               ["nix"] -- Must be empty because we need to return PP.empty from viewAsFieldDescr
-              "Nix integration: run commands through nix-shell if a 'shell.nix' file exists (default is False)"
+              "[DEPRECATED] Nix integration: run commands through nix-shell if a 'shell.nix' file exists (default is False)"
           , noArg
               (Flag True)
               []
               ["enable-nix"]
-              "Enable Nix integration: run commands through nix-shell if a 'shell.nix' file exists"
+              "[DEPRECATED] Enable Nix integration: run commands through nix-shell if a 'shell.nix' file exists"
           , noArg
               (Flag False)
               []
               ["disable-nix"]
-              "Disable Nix integration"
+              "[DEPRECATED] Disable Nix integration"
           ]
       , option
           []

diff --git a/doc/nix-integration.rst b/doc/nix-integration.rst
@@ -1,6 +1,15 @@
 Nix Integration
 ===============
 
+.. warning::
+
+    Nix integration has been deprecated and will be removed in a future release.
+
+    The original mechanism can still be easily replicated with the following commands:
+
+    - for a ``shell.nix``: ``nix-shell --run "cabal ..."``
+    - for a ``flake.nix``: ``nix develop -c cabal ...``
+
 .. note::
 
     This functionality doesn't work with nix-style builds.