Merge https://salsa.debian.org/debian/debhelper

1 files changed, 29 insertions, 9 deletions

diff --git a/dh_dwz b/dh_dwz
index a714c766..471930b9 100755
--- a/dh_dwz
+++ b/dh_dwz
@@ -30,9 +30,17 @@ running L<dwz(1)> on all the ELF binaries in the package.
 =item B<--dwz-multifile>, B<--no-dwz-multifile>
 
 Whether L<dwz(1)> should generate a I<multifile> from the ELF binaries
-in the same package (it does by default).  When enabled, if a package
-ships at least 2 ELF binaries, B<dh_dwz> will instruct L<dwz(1)> to
-generate a multifile for the package.
+in the same package.  When enabled, if a package ships at least 2 ELF
+binaries, B<dh_dwz> will instruct L<dwz(1)> to generate a multifile
+for the package.
+
+By default, B<dh_dwz> will attempt to create a multifile but will
+continue without if L<dwz(1)> does create one (but succeeds anyway).
+This commonly happens when the debug files do not contain debug
+symbols (e.g. a missing -g to the compiler) or when the debug
+symbols are compressed (see Debian bug #931891).  If B<--dwz-multifile>
+is passed, then B<dh_dwz> will abort with an error if L<dwz(1)> does
+not create a multifile.
 
 Note this options may not work if a package contains more ELF binaries
 than can fit on a single command line.  If this becomes a problem,
@@ -41,6 +49,10 @@ please pass B<--no-dwz-multifile> to work around the issue.
 The generated multifile will be compressed with B<objcopy
 --compress-debug-sections>.
 
+Note for B<udeb> packages: B<dh_dwz> will never generate multifiles
+for B<udeb> packages.  It will still use B<dwz> to reduce the
+file size of debug files if it finds any.
+
 =item B<-X>I<item>, B<--exclude=>I<item>
 
 Exclude files that contain I<item> anywhere in their filename from being
@@ -68,7 +80,7 @@ test"-cycles) rather than optimizing for size.
 
 =cut
 
-my $create_multifile = 1;
+my $create_multifile = 'auto';
 
 init(options => {
 	'dwz-multifile!' => \$create_multifile,
@@ -112,18 +124,26 @@ for my $package (@{$dh{DOPACKAGES}}) {
 	# Consistent order;
 	@elf_files = sort(@elf_files);
 	my ($unique_files, $hardlinks) = find_hardlinks(@elf_files);
-	my @dwz_options;
-	if ($create_multifile and @{$unique_files} > 1) {
+	if ($create_multifile and @{$unique_files} > 1 and not is_udeb($package)) {
 		my $objcopy = cross_command($package, 'objcopy');
 		my $ma_dir = dpkg_architecture_value('DEB_HOST_MULTIARCH');
 		my $dwz_dir = "usr/lib/debug/.dwz/${ma_dir}";
 		my $m = "${dwz_dir}/${package}.debug";
 		my @dwz_options = ("-m${tmp}/${m}", "-M/${m}");
 		install_dir("${tmp}/${dwz_dir}");
-		doit('dwz', '-q', @dwz_options, @{$dh{U_PARAMS}}, '--', @{$unique_files});
-		doit($objcopy, '--compress-debug-sections', "${tmp}/${m}");
+		doit('dwz', @dwz_options, @{$dh{U_PARAMS}}, '--', @{$unique_files});
+		if ( -f "${tmp}/${m}") {
+			doit($objcopy, '--compress-debug-sections', "${tmp}/${m}");
+		} else {
+			error("dwz failed to create a multifile as requested") if $create_multifile ne 'auto';
+			warning("No dwz multifile created, but not explicitly requested either so ignoring it.");
+			warning("Common issues include no debug information at all (missing -g) and");
+			warning("compressed debug information (#931891).");
+			# Clean up after ourselves to avoid leaving empty directories in packages
+			doit('rmdir', '-p', '--ignore-fail-on-non-empty', "${tmp}/usr/lib/debug/.dwz/${ma_dir}");
+		}
 	} else {
-		xargs($unique_files, 'dwz', '-q', @{$dh{U_PARAMS}}, '--');
+		xargs($unique_files, 'dwz', @{$dh{U_PARAMS}}, '--');
 	}