From af482b46bc7d8f5efda6305a49c99aa60812d044 Mon Sep 17 00:00:00 2001
From: Francesco Gazzetta <francygazz@gmail.com>
Date: Wed, 16 Jan 2019 17:00:12 +0100
Subject: [PATCH] Prevent dependency on private library

---
 Cabal/Distribution/Simple/Configure.hs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/Cabal/Distribution/Simple/Configure.hs b/Cabal/Distribution/Simple/Configure.hs
index 732753d8013..9e36eebf477 100644
--- a/Cabal/Distribution/Simple/Configure.hs
+++ b/Cabal/Distribution/Simple/Configure.hs
@@ -83,6 +83,7 @@ import Distribution.Types.LegacyExeDependency
 import Distribution.Types.PkgconfigDependency
 import Distribution.Types.LocalBuildInfo
 import Distribution.Types.LibraryName
+import Distribution.Types.LibraryVisibility
 import Distribution.Types.ComponentRequestedSpec
 import Distribution.Types.ForeignLib
 import Distribution.Types.ForeignLibType
@@ -899,9 +900,9 @@ dependencySatisfiable
 
           || all
                (\lib ->
-                 (depName, CLibName lib)
-                 `Map.member`
-                 requiredDepsMap)
+                 let maybeIPI =
+                       (depName, CLibName lib) `Map.lookup` requiredDepsMap
+                 in (Just LibraryVisibilityPublic) == (Installed.libVisibility <$> maybeIPI))
                sublibs
 
     | isInternalDep
@@ -965,7 +966,7 @@ configureFinalizedPackage verbosity cfg enabled
                    pkg_descr0
             of Right r -> return r
                Left missing ->
-                   die' verbosity $ "Encountered missing dependencies:\n"
+                   die' verbosity $ "Encountered missing or private dependencies:\n"
                      ++ (render . nest 4 . sep . punctuate comma
                                 . map (pretty . simplifyDependency)
                                 $ missing)