fix: cabal sdist target selection (#11385)

cabal-install/src/Distribution/Client/CmdSdist.hs

@@ -115,13 +115,10 @@ import Distribution.Simple.Utils
   ( dieWithException
   , notice
   , ordNub
+  , ordNubBy
   , withOutputMarker
   , wrapText
   )
-import Distribution.Types.ComponentName
-  ( ComponentName
-  , showComponentName
-  )
 import Distribution.Types.GenericPackageDescription (GenericPackageDescription)
 import Distribution.Types.PackageName
   ( PackageName
@@ -376,7 +373,7 @@ packageToSdist verbosity projectRootDir format outputFile pkg = do
 reifyTargetSelectors :: [PackageSpecifier UnresolvedSourcePackage] -> [TargetSelector] -> Either [TargetProblem] [UnresolvedSourcePackage]
 reifyTargetSelectors pkgs sels =
   case partitionEithers (foldMap go sels) of
-    ([], sels') -> Right sels'
+    ([], sels') -> Right (ordNubBy packageId sels')
     (errs, _) -> Left errs
   where
     -- there can be pkgs which are in extra-packages:
@@ -401,24 +398,22 @@ reifyTargetSelectors pkgs sels =
     go (TargetAllPackages (Just kind)) = [Left (AllComponentsOnly kind)]
     go (TargetPackageNamed pname _) = [Left (NonlocalPackageNotAllowed pname)]
     go (TargetComponentUnknown pname _ _) = [Left (NonlocalPackageNotAllowed pname)]
-    go (TargetComponent _ cname _) = [Left (ComponentsNotAllowed cname)]
+    -- sdist only packages whole packages, so any target selector referring to a
+    -- component (or a module/file within a component) of a local package selects
+    -- that package. (#11385: a bare package name typed inside the package directory
+    -- resolves to its primary library component, which shadowed the package match.)
+    go (TargetComponent pid _ _) = [getPkg pid]
 
 data TargetProblem
   = AllComponentsOnly ComponentKind
   | NonlocalPackageNotAllowed PackageName
-  | ComponentsNotAllowed ComponentName
 
 renderTargetProblem :: TargetProblem -> String
 renderTargetProblem (AllComponentsOnly kind) =
   "It is not possible to package only the "
     ++ renderComponentKind Plural kind
     ++ " from a package "
     ++ "for distribution. Only entire packages may be packaged for distribution."
-renderTargetProblem (ComponentsNotAllowed cname) =
-  "The component "
-    ++ showComponentName cname
-    ++ " cannot be packaged for distribution on its own. "
-    ++ "Only entire packages may be packaged for distribution."
 renderTargetProblem (NonlocalPackageNotAllowed pname) =
   "The package "
     ++ unPackageName pname

cabal-testsuite/PackageTests/NewSdist/MultiTarget/valid-and-test-suite.out

@@ -1,3 +1,5 @@
 # cabal v2-sdist
-Error: [Cabal-7151]
-The component test suite 'a-tests' cannot be packaged for distribution on its own. Only entire packages may be packaged for distribution.
+Wrote tarball sdist to <ROOT>/dist-newstyle/sdist/a-0.1.tar.gz
+Wrote tarball sdist to <ROOT>/dist-newstyle/sdist/b-0.1.tar.gz
+# cabal v2-sdist
+Wrote source list to <ROOT>/lists/a-0.1.list

cabal-testsuite/PackageTests/NewSdist/MultiTarget/valid-and-test-suite.test.hs

@@ -1,6 +1,15 @@
 import Test.Cabal.Prelude
+import System.Directory (createDirectoryIfMissing)
+import System.FilePath (normalise)
 main = cabalTest $ do
   cwd <- fmap testCurrentDir getTestEnv
-  fails $ cabal "v2-sdist" ["a", "b", "a-tests"]
-  shouldNotExist $ cwd </> "dist-newstyle/sdist/a-0.1.tar.gz"
-  shouldNotExist $ cwd </> "dist-newstyle/sdist/b-0.1.tar.gz"
+  liftIO $ createDirectoryIfMissing False $ cwd </> "lists"
+  cabal "v2-sdist" ["a", "b", "a-tests"]
+  shouldExist $ cwd </> "dist-newstyle/sdist/a-0.1.tar.gz"
+  shouldExist $ cwd </> "dist-newstyle/sdist/b-0.1.tar.gz"
+
+  -- Duplicate selectors resolving to the same package must yield a single
+  -- package, not two copies of the archive (#11385).  With --list-only the
+  -- deduped package is written to a single .list file.
+  cabal "v2-sdist" ["a", "a-tests", "--list-only", "--output-dir", "lists"]
+  assertFindInFile (normalise "a/a.cabal") (cwd </> "lists/a-0.1.list")

cabal-testsuite/PackageTests/NewSdist/SubDirPackageTarget/cabal.project

@@ -0,0 +1 @@
+packages: p/

cabal-testsuite/PackageTests/NewSdist/SubDirPackageTarget/p/P.hs

@@ -0,0 +1 @@
+module P where

cabal-testsuite/PackageTests/NewSdist/SubDirPackageTarget/p/p.cabal

@@ -0,0 +1,7 @@
+cabal-version: 2.2
+name: p
+version: 0.1
+
+library
+  default-language: Haskell2010
+  exposed-modules: P

cabal-testsuite/PackageTests/NewSdist/SubDirPackageTarget/subdir-target.out

@@ -0,0 +1,8 @@
+# cabal v2-sdist
+Configuration is affected by cabal.project at '<GBLTMPDIR>'.
+Wrote tarball sdist to <ROOT>/dist-newstyle/sdist/p-0.1.tar.gz
+# cabal v2-sdist
+Configuration is affected by cabal.project at '<GBLTMPDIR>'.
+Wrote tarball sdist to <ROOT>/dist-newstyle/sdist/p-0.1.tar.gz
+# cabal v2-sdist
+Wrote tarball sdist to <ROOT>/dist-newstyle/sdist/p-0.1.tar.gz

cabal-testsuite/PackageTests/NewSdist/SubDirPackageTarget/subdir-target.test.hs

@@ -0,0 +1,10 @@
+import Test.Cabal.Prelude
+main = cabalTest $ do
+  cwd <- fmap testCurrentDir getTestEnv
+  -- #11385: bare package name typed inside the package directory
+  withDirectory "p" $ cabal "v2-sdist" ["p"]
+  -- explicit component form selects the containing package
+  withDirectory "p" $ cabal "v2-sdist" ["p:lib:p"]
+  -- package name from the project root keeps working
+  cabal "v2-sdist" ["p"]
+  shouldExist $ cwd </> "dist-newstyle/sdist/p-0.1.tar.gz"

changelog.d/11385.md

@@ -0,0 +1,18 @@
+---
+synopsis: "`cabal sdist <pkg>` works when run inside the package directory"
+packages: [cabal-install]
+prs: 12440
+issues: 11385
+---
+
+`cabal sdist <pkgname>` failed with `[Cabal-7151] The component library cannot be
+packaged for distribution on its own` when run inside the package directory,
+because a bare package name resolves to the package's primary library component.
+Any target selector referring to a component (or a module or file within a
+component) of a local package now selects that package, so `cabal sdist <pkg>`,
+`cabal sdist <pkg>:lib:<pkg>` and similar forms package the containing package.
+Explicit component-kind filters such as `cabal sdist tests` still fail with
+`[Cabal-7151]`. Multiple selectors resolving to the same package (e.g.
+`cabal sdist a a-tests`) now produce a single archive per package instead of
+duplicates, and `cabal sdist a a-tests --output-dir -` writes one tarball to
+standard output rather than failing with `[Cabal-7152]`.