pack: Add relocation via ld.so and fakechroot.

* gnu/packages/aux-files/run-in-namespace.c (HAVE_EXEC_WITH_LOADER): New
macro.
(bind_mount): Rename to...
(mirror_directory): ... this.  Add 'firmlink' argument and use it
instead of calling mkdir/open/close/mount directly.
(bind_mount, make_symlink): New functions.
(exec_in_user_namespace): Adjust accordingly.
(exec_with_loader) [HAVE_EXEC_WITH_LOADER]: New function.
(exec_performance): New function.
(engines): Add them.
* guix/scripts/pack.scm (wrapped-package)[fakechroot-library]
[audit-module]: New procedures.
[audit-source]: New variable.
[build](elf-interpreter, elf-loader-compile-flags): New procedures.
(build-wrapper): Use them.
* tests/guix-pack-relocatable.sh: Test with
'GUIX_EXECUTION_ENGINE=fakechroot'.
* doc/guix.texi (Invoking guix pack): Document the 'performance' and
'fakechroot' engines.
* gnu/packages/aux-files/pack-audit.c: New file.
* Makefile.am (AUX_FILES): Add it.

1 files changed, 6 insertions, 0 deletions

diff --git a/tests/guix-pack-relocatable.sh b/tests/guix-pack-relocatable.sh
index cb56815fed..358cac5b26 100644
--- a/tests/guix-pack-relocatable.sh
+++ b/tests/guix-pack-relocatable.sh
@@ -94,6 +94,12 @@ case "`uname -m`" in
 	export GUIX_EXECUTION_ENGINE
 	"$test_directory/Bin/sed" --version > "$test_directory/output"
 	grep 'GNU sed' "$test_directory/output"
+
+	# Now with fakechroot.
+	GUIX_EXECUTION_ENGINE="fakechroot"
+	"$test_directory/Bin/sed" --version > "$test_directory/output"
+	grep 'GNU sed' "$test_directory/output"
+
 	chmod -Rf +w "$test_directory"; rm -rf "$test_directory"/*
 	;;
     *)