[Buildroot] [PATCH v5 08/19] reproducible: try to detect most common errors

[Jérôme Pouiller]

Some package includes some information from build environment in their results.
This practice is incompatible with reproducible builds.

This patch scans final target to research most common patterns.

Since we only search fixed strings (grep is called with -F), this search is
fast (on my station, 60ms for a target of 40MB).

Note, it could be a good idea to also match current user name. However, build
path often contains username and, until now, we do not try to avoid build path
in result.

Signed-off-by: Jérôme Pouiller <jezz at sysmic.org>
---
 Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Makefile b/Makefile
index ad7fde5..5b504c1 100644
--- a/Makefile
+++ b/Makefile
@@ -708,6 +708,11 @@ endif
 		$(call MESSAGE,"Executing post-build script $(s)"); \
 		$(EXTRA_ENV) $(s) $(TARGET_DIR) $(call qstrip,$(BR2_ROOTFS_POST_SCRIPT_ARGS))$(sep))
 
+ifeq ($(BR2_REPRODUCIBLE),y)
+	grep -raoF -e "`uname -r`" -e "`uname -v`" -e "`uname -n`" $(TARGET_DIR) | \
+		sed 's/\(.*\):\(.*\)/Warning: \1 may contain unreproducible information: \2/' | uniq
+endif
+
 target-post-image: $(TARGETS_ROOTFS) target-finalize
 	@$(foreach s, $(call qstrip,$(BR2_ROOTFS_POST_IMAGE_SCRIPT)), \
 		$(call MESSAGE,"Executing post-image script $(s)"); \
-- 
1.9.1