From 40cd496c7be1386582e7378466fac4dad1df34bd Mon Sep 17 00:00:00 2001
From: Edmund Noble <edmundnoble@gmail.com>
Date: Mon, 25 Mar 2024 13:35:35 -0400
Subject: [PATCH] synchronize source repos concurrently

---
 cabal-install/src/Distribution/Client/ProjectConfig.hs | 3 ++-
 changelog.d/synchronize-source-repos-concurrently      | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 changelog.d/synchronize-source-repos-concurrently

diff --git a/cabal-install/src/Distribution/Client/ProjectConfig.hs b/cabal-install/src/Distribution/Client/ProjectConfig.hs
index 97428671936..eca9f26c69e 100644
--- a/cabal-install/src/Distribution/Client/ProjectConfig.hs
+++ b/cabal-install/src/Distribution/Client/ProjectConfig.hs
@@ -1338,12 +1338,13 @@ syncAndReadSourcePackagesRemoteRepos
             ]
 
     let progPathExtra = fromNubList projectConfigProgPathExtra
+    let numJobs = 4 -- hardcoded for now
     getConfiguredVCS <- delayInitSharedResources $ \repoType ->
       let vcs = Map.findWithDefault (error $ "Unknown VCS: " ++ prettyShow repoType) repoType knownVCSs
        in configureVCS verbosity progPathExtra vcs
 
     concat
-      <$> sequenceA
+      <$> sequenceConcurrentlyBoundedRebuild numJobs
         [ rerunIfChanged verbosity monitor repoGroup' $ do
           vcs' <- getConfiguredVCS repoType
           syncRepoGroupAndReadSourcePackages vcs' pathStem repoGroup'
diff --git a/changelog.d/synchronize-source-repos-concurrently b/changelog.d/synchronize-source-repos-concurrently
new file mode 100644
index 00000000000..c220ecfbb97
--- /dev/null
+++ b/changelog.d/synchronize-source-repos-concurrently
@@ -0,0 +1,5 @@
+synopsis: Synchronize source repositories concurrently
+packages: cabal-install
+prs: #0000
+significance: significant
+