Python: improve cross-compilation

This changeset allows for cross-compilation of Python packages. Packages
built with buildPythonPackage are not allowed to refer to the build
machine. Executables that have shebangs will refer to the host.

1 files changed, 9 insertions, 3 deletions

diff --git a/pkgs/development/interpreters/python/wrap.sh b/pkgs/development/interpreters/python/wrap.sh
index 6fa8c316a17..b2d65422db4 100644
--- a/pkgs/development/interpreters/python/wrap.sh
+++ b/pkgs/development/interpreters/python/wrap.sh
@@ -16,8 +16,8 @@ buildPythonPath() {
     declare -A pythonPathsSeen=()
     program_PYTHONPATH=
     program_PATH=
-    pythonPathsSeen["@python@"]=1
-    addToSearchPath program_PATH @python@/bin
+    pythonPathsSeen["@pythonHost@"]=1
+    addToSearchPath program_PATH @pythonHost@/bin
     for path in $pythonPath; do
         _addToPythonPath $path
     done
@@ -53,7 +53,13 @@ wrapPythonProgramsIn() {
             # Strip suffix, like "3" or "2.7m" -- we don't have any choice on which
             # Python to use besides one with this hook anyway.
             if head -n1 "$f" | grep -q '#!.*/env.*\(python\|pypy\)'; then
-                sed -i "$f" -e "1 s^.*/env[ ]*\(python\|pypy\)[^ ]*^#! @executable@^"
+                sed -i "$f" -e "1 s^.*/env[ ]*\(python\|pypy\)[^ ]*^#!@executable@^"
+            fi
+
+            if head -n1 "$f" | grep -q '#!.*'; then
+                # Cross-compilation hack: ensure shebangs are for the host
+                echo "Rewriting $(head -n 1 $f) to #!@pythonHost@"
+                sed -i "$f" -e "1 s^#!@python@^#!@pythonHost@^"
             fi
 
             # catch /python and /.python-wrapped