From 8975b7b0e2f7b02af03175ca4552f74c668b77ca Mon Sep 17 00:00:00 2001
From: cfhammill <cfhammill@gmail.com>
Date: Mon, 13 Jul 2020 17:20:14 -0400
Subject: [PATCH] singularity-tools: Check for /bin/sh existence before symlink

Fixes the case where the user has bashInteractive in the
container contents
---
 pkgs/build-support/singularity-tools/default.nix | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pkgs/build-support/singularity-tools/default.nix b/pkgs/build-support/singularity-tools/default.nix
index 54749e416ea3..cf234abb55fe 100644
--- a/pkgs/build-support/singularity-tools/default.nix
+++ b/pkgs/build-support/singularity-tools/default.nix
@@ -86,7 +86,9 @@ rec {
             done
 
             # Create runScript and link shell
-            ln -s ${runtimeShell} bin/sh
+            if [ ! -e bin/sh ]; then
+              ln -s ${runtimeShell} bin/sh
+            fi
             mkdir -p .singularity.d
             ln -s ${runScriptFile} .singularity.d/runscript