From 23ab6fc29f28b0fa9ad94bf2ceed135ee3fdea34 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Wed, 23 Oct 2024 22:26:34 +0200
Subject: [PATCH] environment: Gracefully handle preexistence of /bin/cc in
 FHS.

* guix/scripts/environment.scm (setup-fhs): When /bin/cc already exists,
keep it.

Reported-by: Marco Fortina <marco_fortina@hotmail.it>
Change-Id: I73d39d2aa6fbafd236061a0e3b8d1fe327b2bb19
---
 guix/scripts/environment.scm | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/guix/scripts/environment.scm b/guix/scripts/environment.scm
index a219b2ac89e..fc7fa84be7b 100644
--- a/guix/scripts/environment.scm
+++ b/guix/scripts/environment.scm
@@ -464,8 +464,15 @@ providing a symlink for CC if GCC is in the container PROFILE, and writing
   ;; /bin since that already has the sh symlink and the other (optional) FHS
   ;; bin directories will link to /bin.
   (let ((gcc-path (string-append profile "/bin/gcc")))
-    (if (file-exists? gcc-path)
-        (symlink gcc-path "/bin/cc")))
+    (when (file-exists? gcc-path)
+      (catch 'system-error
+        (lambda ()
+          (symlink gcc-path "/bin/cc"))
+        (lambda args
+          ;; If /bin/cc already exists because it was provided by another
+          ;; package in PROFILE, such as 'clang-toolchain', leave it.
+          (unless (= EEXIST (system-error-errno args))
+            (apply throw args))))))
 
   ;; Guix's ldconfig doesn't search in FHS default locations, so provide a
   ;; minimal ld.so.conf.