From d63e6b41fcc05059bd51f559229712e4a3998d15 Mon Sep 17 00:00:00 2001
From: Ben Gamari <ben@smart-cactus.org>
Date: Tue, 26 Sep 2023 13:04:13 -0400
Subject: [PATCH] Don't `foreign import` `environ`

`musl` defines the `environ` symbol as a weak alias, which on AArch64
requires particular treatment by the compiler. As GHC doesn't have
access to the prototype of the symbol, it doesn't know that this
treatment is necessary and consequently we emit assembly that the linker
will choke on.

See GHC #24011.
---
 System/Posix/Env/Internal.hsc | 9 ++++++---
 cbits/HsUnix.c                | 2 ++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/System/Posix/Env/Internal.hsc b/System/Posix/Env/Internal.hsc
index d8732a6a..1932b857 100644
--- a/System/Posix/Env/Internal.hsc
+++ b/System/Posix/Env/Internal.hsc
@@ -22,8 +22,11 @@ getCEnviron = nsGetEnviron >>= peek
 foreign import ccall unsafe "_NSGetEnviron"
    nsGetEnviron :: IO (Ptr (Ptr CString))
 #else
-getCEnviron = peek c_environ_p
+getCEnviron = _getCEnviron
 
-foreign import ccall unsafe "&environ"
-   c_environ_p :: Ptr (Ptr CString)
+-- N.B. we cannot import `environ` directly in Haskell as it may be a weak symbol
+-- which requires special treatment by the compiler, which GHC is not equipped to
+-- provide. See GHC #24011.
+foreign import ccall unsafe "__hsunix_get_environ"
+   _getCEnviron :: IO (Ptr CString)
 #endif
diff --git a/cbits/HsUnix.c b/cbits/HsUnix.c
index f2908d06..60d259f3 100644
--- a/cbits/HsUnix.c
+++ b/cbits/HsUnix.c
@@ -8,6 +8,8 @@
 
 #include "HsUnix.h"
 
+char **__hsunix_get_environ (void) {return environ;}
+
 #ifdef HAVE_RTLDNEXT
 void *__hsunix_rtldNext (void) {return RTLD_NEXT;}
 #endif