From 312a4124e3e197e3525f60d5b9684e208e1c8df4 Mon Sep 17 00:00:00 2001
From: Teo Camarasu <teo.camarasu@tracsis.com>
Date: Wed, 24 Apr 2024 11:47:53 +0100
Subject: [PATCH] Downgrade NoLibraryFound from an error to a warning
This makes Setup copy/install succeed if there's
nothing to do because the package doesn't contain
a library or executable.
This allows downstream users of Cabal to avoid having to
add workarounds for this edge case.
Resolves #6750
---
Cabal/src/Distribution/Simple/Errors.hs | 3 ++-
Cabal/src/Distribution/Simple/Install.hs | 2 +-
.../OnlyTestSuite/OnlyTestSuite.cabal | 15 +++++++++++++++
.../PackageTests/OnlyTestSuite/cabal.cabal.out | 6 ++++++
.../PackageTests/OnlyTestSuite/cabal.out | 6 ++++++
.../PackageTests/OnlyTestSuite/cabal.test.hs | 6 ++++++
.../PackageTests/OnlyTestSuite/test/Main.hs | 4 ++++
changelog.d/issue-6750 | 13 +++++++++++++
8 files changed, 53 insertions(+), 2 deletions(-)
create mode 100644 cabal-testsuite/PackageTests/OnlyTestSuite/OnlyTestSuite.cabal
create mode 100644 cabal-testsuite/PackageTests/OnlyTestSuite/cabal.cabal.out
create mode 100644 cabal-testsuite/PackageTests/OnlyTestSuite/cabal.out
create mode 100644 cabal-testsuite/PackageTests/OnlyTestSuite/cabal.test.hs
create mode 100644 cabal-testsuite/PackageTests/OnlyTestSuite/test/Main.hs
create mode 100644 changelog.d/issue-6750
diff --git a/Cabal/src/Distribution/Simple/Errors.hs b/Cabal/src/Distribution/Simple/Errors.hs
index 45029565e9..8513f92c7b 100644
--- a/Cabal/src/Distribution/Simple/Errors.hs
+++ b/Cabal/src/Distribution/Simple/Errors.hs
@@ -47,7 +47,8 @@ data CabalException
| EnableBenchMark
| BenchMarkNameDisabled String
| NoBenchMark String
- | NoLibraryFound
+ | -- | @NoLibraryFound@ has been downgraded to a warning, and is therefore no longer emitted.
+ NoLibraryFound
| CompilerNotInstalled CompilerFlavor
| CantFindIncludeFile String
| UnsupportedTestSuite String
diff --git a/Cabal/src/Distribution/Simple/Install.hs b/Cabal/src/Distribution/Simple/Install.hs
index c1134e2b35..c46f28b352 100644
--- a/Cabal/src/Distribution/Simple/Install.hs
+++ b/Cabal/src/Distribution/Simple/Install.hs
@@ -147,7 +147,7 @@ install_setupHooks
checkHasLibsOrExes =
unless (hasLibs pkg_descr || hasForeignLibs pkg_descr || hasExes pkg_descr) $
- dieWithException verbosity NoLibraryFound
+ warn verbosity "No executables and no library found. Nothing to do."
-- | Copy package global files.
copyPackage
diff --git a/cabal-testsuite/PackageTests/OnlyTestSuite/OnlyTestSuite.cabal b/cabal-testsuite/PackageTests/OnlyTestSuite/OnlyTestSuite.cabal
new file mode 100644
index 0000000000..c449f91998
--- /dev/null
+++ b/cabal-testsuite/PackageTests/OnlyTestSuite/OnlyTestSuite.cabal
@@ -0,0 +1,15 @@
+cabal-version: 3.0
+name: OnlyTestSuite
+version: 0.1.0.0
+build-type: Simple
+
+common warnings
+ ghc-options: -Wall
+
+test-suite OnlyTestSuite-test
+ import: warnings
+ default-language: Haskell2010
+ type: exitcode-stdio-1.0
+ hs-source-dirs: test
+ main-is: Main.hs
+ build-depends: base
diff --git a/cabal-testsuite/PackageTests/OnlyTestSuite/cabal.cabal.out b/cabal-testsuite/PackageTests/OnlyTestSuite/cabal.cabal.out
new file mode 100644
index 0000000000..829de87b0c
--- /dev/null
+++ b/cabal-testsuite/PackageTests/OnlyTestSuite/cabal.cabal.out
@@ -0,0 +1,6 @@
+# Setup configure
+Configuring OnlyTestSuite-0.1.0.0...
+# Setup build
+Building OnlyTestSuite-0.1.0.0...
+# Setup copy
+Warning: No executables and no library found. Nothing to do.
diff --git a/cabal-testsuite/PackageTests/OnlyTestSuite/cabal.out b/cabal-testsuite/PackageTests/OnlyTestSuite/cabal.out
new file mode 100644
index 0000000000..829de87b0c
--- /dev/null
+++ b/cabal-testsuite/PackageTests/OnlyTestSuite/cabal.out
@@ -0,0 +1,6 @@
+# Setup configure
+Configuring OnlyTestSuite-0.1.0.0...
+# Setup build
+Building OnlyTestSuite-0.1.0.0...
+# Setup copy
+Warning: No executables and no library found. Nothing to do.
diff --git a/cabal-testsuite/PackageTests/OnlyTestSuite/cabal.test.hs b/cabal-testsuite/PackageTests/OnlyTestSuite/cabal.test.hs
new file mode 100644
index 0000000000..6e715d370e
--- /dev/null
+++ b/cabal-testsuite/PackageTests/OnlyTestSuite/cabal.test.hs
@@ -0,0 +1,6 @@
+import Test.Cabal.Prelude
+main = setupAndCabalTest $ do
+ withPackageDb $ do
+ setup "configure" []
+ setup "build" []
+ setup "copy" []
diff --git a/cabal-testsuite/PackageTests/OnlyTestSuite/test/Main.hs b/cabal-testsuite/PackageTests/OnlyTestSuite/test/Main.hs
new file mode 100644
index 0000000000..3e2059e31f
--- /dev/null
+++ b/cabal-testsuite/PackageTests/OnlyTestSuite/test/Main.hs
@@ -0,0 +1,4 @@
+module Main (main) where
+
+main :: IO ()
+main = putStrLn "Test suite not yet implemented."
diff --git a/changelog.d/issue-6750 b/changelog.d/issue-6750
new file mode 100644
index 0000000000..e392258267
--- /dev/null
+++ b/changelog.d/issue-6750
@@ -0,0 +1,13 @@
+synopsis: Make Setup copy/install succeed when there's no executable or library
+packages: Cabal
+prs: #9926
+issues: #6750
+
+description: {
+ Historically the Setup copy and install steps would fail if the package didn't
+ contain an executable or library component. In this case there's nothing to do.
+
+ This required workarounds for downstream users of Cabal to handle this edge case.
+ Now that this error has been downgraded to a warning, Cabal will succeed if
+ there's nothing to do.
+}
--
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