From 3832beaf50b9ec7d07111ce0f673de95577f48a9 Mon Sep 17 00:00:00 2001
From: Jens Petersen <petersen@redhat.com>
Date: Fri, 3 Nov 2023 16:30:40 +0800
Subject: [PATCH] cabal-install-solver: fix pkgconf 1.9 --modversion regression

Check that the numbers of *versions* output is equal to the number of pkgconf's

fixes #8923

The pkgconf behavior was reverted upstream in 2.0

(this should cover the case too of checking that equal pkgList lines are output also)
---
 .../src/Distribution/Solver/Types/PkgConfigDb.hs           | 7 ++++---
 changelog.d/pr-9391                                        | 4 ++++
 2 files changed, 8 insertions(+), 3 deletions(-)
 create mode 100644 changelog.d/pr-9391

diff --git a/cabal-install-solver/src/Distribution/Solver/Types/PkgConfigDb.hs b/cabal-install-solver/src/Distribution/Solver/Types/PkgConfigDb.hs
index 00bc38c28c3..ee2f22032ca 100644
--- a/cabal-install-solver/src/Distribution/Solver/Types/PkgConfigDb.hs
+++ b/cabal-install-solver/src/Distribution/Solver/Types/PkgConfigDb.hs
@@ -67,11 +67,12 @@ readPkgConfigDb verbosity progdb = handle ioErrorHandler $ do
         -- The output of @pkg-config --list-all@ also includes a description
         -- for each package, which we do not need.
         let pkgNames = map (takeWhile (not . isSpace)) pkgList
-        (pkgVersions, _errs, exitCode) <-
+        (outs, _errs, exitCode) <-
                      getProgramInvocationOutputAndErrors verbosity
                        (programInvocation pkgConfig ("--modversion" : pkgNames))
-        if exitCode == ExitSuccess && length pkgNames == length pkgList
-          then (return . pkgConfigDbFromList . zip pkgNames) (lines pkgVersions)
+        let pkgVersions = lines outs
+        if exitCode == ExitSuccess && length pkgVersions == length pkgNames
+          then (return . pkgConfigDbFromList . zip pkgNames) pkgVersions
           else
           -- if there's a single broken pc file the above fails, so we fall back
           -- into calling it individually
diff --git a/changelog.d/pr-9391 b/changelog.d/pr-9391
new file mode 100644
index 00000000000..517c94ed127
--- /dev/null
+++ b/changelog.d/pr-9391
@@ -0,0 +1,4 @@
+synopsis: fix pkgconfig-depends for pkgconf-1.9
+packages: cabal-install-solver
+prs: #9391
+issues: #8923