Package: dpkg-cross
Version: 2.6.15-3
Tags: patch
User: helm...@debian.org
Usertags: rebootstrap
This is a complex issue. Please take some time to understand it.
When using dpkg-cross to convert a library package it simply copies the
shlibs file. A shlibs file for libc6 for example contains the line:
libc 6 libc6 (>= 2.30)
The part after the second space is a dependency. When the original
package was e.g. libc6:mipsel, the converted package becomes
libc6-mipsel-cross:all. Now when dpkg-shlibdeps encounters a library
from libc6-mipsel-cross:all, it issues the relevant "libc6 (>= 2.30)"
dependency. However libc6-mipsel-cross:all is treated as a native
architecture (usually amd64). The inserted dependency lacks an
architecture qualifier.
The gcc-N packages need this architecture qualifier to convert them into
the usual -$arch-cross suffix. It has a cross_mangle_substvars to do
that:
https://salsa.debian.org/toolchain-team/gcc/-/blob/master/debian/rules.defs#L2203
When that suffix is missing, the issued dependency lacks the
-$arch-cross suffix. The cross-toolchain-base package takes care to
update shlibs files, see:
https://salsa.debian.org/toolchain-team/cross-toolchain-base/-/blob/master/debian/rules#L787
For doing that, cross-toolchain-base repacks the .deb twice. Once using
dpkg-cross and once using its repack target. It would make much more
sense to have this shlibs transformation inside dpkg-cross directly.
What does this mean in practise?
When you perform a toolchain bootstrap without cross-toolchain-base, you
end up without this shlibs fixup and when you build the gcc stage3 cross
compiler, you end up with support libraries with wrong dependencies:
dpkg: dependency problems prevent configuration of
lib64atomic1-mipsel-cross:
lib64atomic1-mipsel-cross depends on libc6-mips64 (>= 2.30); however:
Package libc6-mips64 is not installed.
dpkg: error processing package lib64atomic1-mipsel-cross (--install):
dependency problems - leaving unconfigured
After applying the attached patch, the generated dependencies in
multilib packages become correct. For non-multilib packages it also
happens to be wrong, but libatomic1-mipsel-cross simply depends on libc6
then. Doing so resolves to the native libc6 and dpkg is happy even when
libc6-mipsel-cross is missing.
The missing arch qualification is not a problem if you build "regular"
packages using dpkg-cross'ed packages. It only is a problem if you
attempt to produce dpkg-cross-style packages such as how gcc does it.
However, gcc nowadays is the main consumer of dpkg-cross'ed packages, so
we should make that experience painless.
So please consider applying the attached patch.
Helmut
diff --minimal -Nru dpkg-cross-2.6.15/debian/changelog
dpkg-cross-2.6.15/debian/changelog
--- dpkg-cross-2.6.15/debian/changelog 2019-05-26 23:33:37.000000000 +0200
+++ dpkg-cross-2.6.15/debian/changelog 2020-04-03 15:33:57.000000000 +0200
@@ -1,3 +1,10 @@
+dpkg-cross (2.6.15-3.1) UNRELEASED; urgency=medium
+
+ * Non-maintainer upload.
+ * Arch qualify dependencies in shlibs files. (Closes: #-1)
+
+ -- Helmut Grohne <hel...@subdivi.de> Fri, 03 Apr 2020 15:33:57 +0200
+
dpkg-cross (2.6.15-3) unstable; urgency=medium
[ Helmut Grohne ]
diff --minimal -Nru dpkg-cross-2.6.15/dpkg-cross dpkg-cross-2.6.15/dpkg-cross
--- dpkg-cross-2.6.15/dpkg-cross 2017-07-24 17:47:10.000000000 +0200
+++ dpkg-cross-2.6.15/dpkg-cross 2020-04-03 15:33:57.000000000 +0200
@@ -744,6 +744,35 @@
close(TO);
return 1;
}
+ # Helper: fix shlibs file
+ # - arch-qualify dependencies
+ sub fix_shlibs($$) {
+ my ($from, $to) = @_;
+ ensure_dir($to) or return 0;
+ if (! open(FROM, $from)) {
+ $msg = sprintf(_g("%s: failed to open %s: %s\n"),
$progname, $from, $!);
+ warn ($msg);
+ return 0;
+ }
+ if (! open(TO, ">$to")) {
+ $msg = sprintf(_g("%s: failed to open %s for writing:
%s\n"), $progname, $to, $!);
+ warn ($msg);
+ close(FROM);
+ return 0;
+ }
+ while (<FROM>) {
+ if (m/^#/) {
+ print TO;
+ } elsif (m/((?:\S+:\s*)?\S+\s+\S+\s+)(.*)/) {
+ print TO ($1 . join(",", map { s/\S+/$&:$arch/;
$_; } split(/,/, $2)) . "\n");
+ } else {
+ print TO;
+ }
+ }
+ close(FROM);
+ close(TO);
+ return 1;
+ }
my $config = &get_config;
$crosstype = `CC="" dpkg-architecture -f -a$arch -qDEB_HOST_GNU_TYPE 2>
/dev/null`;
chomp ($crosstype);
@@ -1089,7 +1118,7 @@
# Link the shlibs file
if (-f "$src/DEBIAN/shlibs") {
print "Installing shlibs file\n" if $verbose >= 2;
- link_file("$src/DEBIAN/shlibs", "$dst/DEBIAN/shlibs");
+ fix_shlibs("$src/DEBIAN/shlibs", "$dst/DEBIAN/shlibs");
}
# Create the control file.
