Re: Weird behavior in glibc Makefiles, or: another example why you should never build software as root user (was: r5848 - in glibc-package/branches/eglibc-2.18/debian: . rules.d)

[Aurélien Jarno <aurelien at aurel32 dot net>]

Hi!

On Wed, Dec 04, 2013 at 03:56:01PM +0100, Thomas Schwinge wrote:
> Hi!
> 
> Just seen this in the Debian glibc development repository:
> 
> On Sun,  1 Dec 2013 21:20:24 +0000, Aurelien Jarno <aurel32@moszumanska.debian.org> wrote:
> > Author: aurel32
> > Date: 2013-12-01 21:20:24 +0000 (Sun, 01 Dec 2013)
> > New Revision: 5848
> 
> > --- glibc-package/branches/eglibc-2.18/debian/rules.d/build.mk	2013-12-01 21:03:01 UTC (rev 5847)
> > +++ glibc-package/branches/eglibc-2.18/debian/rules.d/build.mk	2013-12-01 21:20:24 UTC (rev 5848)
> > @@ -57,6 +57,11 @@
> >  	echo "slibdir = $(call xx,slibdir)"       >> $(DEB_BUILDDIR)/configparms
> >  	echo "rtlddir = $(call xx,rtlddir)"       >> $(DEB_BUILDDIR)/configparms
> >  
> > +	# Define the installation directory for all calls to make. This avoid
> > +	# broken glibc makefiles to spuriously trigger install rules trying to
> > +	# overwrite system headers.
> > +	echo "install_root = $(CURDIR)/debian/tmp-$(curpass)" >> $(DEB_BUILDDIR)/configparms
> 
> Just for reference, this very much looks like the issue (as well as the
> "solution") that I've described in
> <http://news.gmane.org/find-root.php?message_id=%3C871uv99c59.fsf%40kepler.schwinge.homeip.net%3E>.

It is actually except it is on different file, and it is inspired by
your trick. I was just worried that a file is really installed and a
directory created at the same time, so instead of adding code to to 
remove this directory later in debian/rules, I have chosen to use the
final directory where the files are eventually going to be installed.
Worst case the header is going to get reinstalled during the make
install phase.

> Someone ;-) should be doing something about this eventually.

I tried a few things, that seemd to work, but they had side effects. The
best workaround I have found is the following:

diff --git a/Makerules b/Makerules
index 92c2872..4fd5f76 100644
--- a/Makerules
+++ b/Makerules
@@ -328,7 +328,7 @@ endif # $(build-shared) = yes
 endif # sysd-sorted-done
 
 # Generate .dT files as we compile.
-compile-mkdep-flags = -MD -MP -MF $@.dt -MT $@
+compile-mkdep-flags = -MMD -MP -MF $@.dt -MT $@
 compile-command.S = $(compile.S) $(OUTPUT_OPTION) $(compile-mkdep-flags)
 compile-command.c = $(compile.c) $(OUTPUT_OPTION) $(compile-mkdep-flags)
 compile-command.cc = $(compile.cc) $(OUTPUT_OPTION) $(compile-mkdep-flags)

That said if a system header is modified intentionally, the affected
files in the glibc build won't be rebuilt anymore. It should be fine for
a package, but not for upstream development.

-- 
Aurelien Jarno	                        GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net