From 37205ba11b0972e36eb320c1a086bf574f654feb Mon Sep 17 00:00:00 2001
From: sheaf <sam.derbyshire@gmail.com>
Date: Wed, 18 Jun 2025 12:52:37 +0200
Subject: [PATCH] cabal-install: dynExe+profExe requires prof+dyn

This commit updates the logic in cabal-install's 'elaborateInstallPlan'
function to ensure that we don't try to build a profiled dynamic
executable if the compiler doesn't support the profiling dynamic way.

This brings the logic in cabal-install in sync with the Cabal
'configureProfiling' function, which sets 'withDynExe' to false if the
user wants a profiled executable but prof+dyn is not supported by the
compiler.
---
 Cabal/src/Distribution/Simple/Compiler.hs            | 12 +++++++-----
 .../src/Distribution/Client/ProjectPlanning.hs       | 11 +++++++++--
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/Cabal/src/Distribution/Simple/Compiler.hs b/Cabal/src/Distribution/Simple/Compiler.hs
index 346c4c82125..6c81b50f891 100644
--- a/Cabal/src/Distribution/Simple/Compiler.hs
+++ b/Cabal/src/Distribution/Simple/Compiler.hs
@@ -509,11 +509,13 @@ profilingVanillaSupported comp = waySupported "p" comp
 
 -- | Is the compiler distributed with profiling dynamic libraries
 profilingDynamicSupported :: Compiler -> Maybe Bool
-profilingDynamicSupported comp =
-  -- Certainly not before this version, as it was not implemented yet.
-  if compilerVersion comp <= mkVersion [9, 11, 0]
-    then Just False
-    else waySupported "p_dyn" comp
+profilingDynamicSupported comp
+  | GHC <- compilerFlavor comp
+  , -- Certainly not before 9.11, as prof+dyn was not implemented yet.
+    compilerVersion comp <= mkVersion [9, 11, 0] =
+      Just False
+  | otherwise =
+      waySupported "p_dyn" comp
 
 -- | Either profiling dynamic is definitely supported or we don't know (so assume
 -- it is)
diff --git a/cabal-install/src/Distribution/Client/ProjectPlanning.hs b/cabal-install/src/Distribution/Client/ProjectPlanning.hs
index f6b27eafca2..fbd4f758d67 100644
--- a/cabal-install/src/Distribution/Client/ProjectPlanning.hs
+++ b/cabal-install/src/Distribution/Client/ProjectPlanning.hs
@@ -2316,10 +2316,15 @@ elaborateInstallPlan
                 { withVanillaLib = perPkgOptionFlag pkgid True packageConfigVanillaLib -- TODO: [required feature]: also needs to be handled recursively
                 , withSharedLib = canBuildSharedLibs && pkgid `Set.member` pkgsUseSharedLibrary
                 , withStaticLib = perPkgOptionFlag pkgid False packageConfigStaticLib
-                , withDynExe = perPkgOptionFlag pkgid False packageConfigDynExe
+                , withDynExe =
+                    perPkgOptionFlag pkgid False packageConfigDynExe
+                      -- We can't produce a dynamic executable if the user
+                      -- wants to enable executable profiling but the
+                      -- compiler doesn't support prof+dyn.
+                      && (okProfDyn || not profExe)
                 , withFullyStaticExe = perPkgOptionFlag pkgid False packageConfigFullyStaticExe
                 , withGHCiLib = perPkgOptionFlag pkgid False packageConfigGHCiLib -- TODO: [required feature] needs to default to enabled on windows still
-                , withProfExe = perPkgOptionFlag pkgid False packageConfigProf
+                , withProfExe = profExe
                 , withProfLib = canBuildProfilingLibs && pkgid `Set.member` pkgsUseProfilingLibrary
                 , withProfLibShared = canBuildProfilingSharedLibs && pkgid `Set.member` pkgsUseProfilingLibraryShared
                 , exeCoverage = perPkgOptionFlag pkgid False packageConfigCoverage
@@ -2334,6 +2339,8 @@ elaborateInstallPlan
                 , withProfLibDetail = elabProfExeDetail
                 , withProfExeDetail = elabProfLibDetail
                 }
+            okProfDyn = profilingDynamicSupportedOrUnknown compiler
+            profExe = perPkgOptionFlag pkgid False packageConfigProf
 
             ( elabProfExeDetail
               , elabProfLibDetail