collect-dbgsym: Skip Multi-Arch: no -dbgsym packages for foreign archs

Ubuntu 12.04 somehow has libnss3-dbgsym and libnspr4-dbgsym packages
that are Multi-Arch: no, even though their corresponding libraries are
Multi-Arch: same.
Signed-off-by: Simon McVittie <smcv@collabora.com>

flatdeb/collect-dbgsym

@@ -57,6 +57,11 @@ class InstalledPackage:
         self.binary_version = fields[1]
         self.source = fields[2] or self.binary
 
+        if ':' not in self.qualified_binary:
+            self.architecture = None    # type: typing.Optional[str]
+        else:
+            self.architecture = self.qualified_binary.split(':')[-1]
+
     def __str__(self):
         # type: () -> str
         return '{}_{}'.format(self.qualified_binary, self.binary_version)
@@ -120,6 +125,7 @@ def main():
     parser = argparse.ArgumentParser(
         description='Install corresponding -dbgsym packages if available',
     )
+    parser.add_argument('--primary-architecture', default=None)
     parser.add_argument('--debug', action='store_true', default=False)
     parser.add_argument('sysroot')
 
@@ -156,6 +162,12 @@ def main():
         to_inspect.add(
             '{}={}'.format(want.qualified_dbgsym_package, want.binary_version))
 
+    if args.primary_architecture is None:
+        args.primary_architecture = subprocess.run(
+            in_chroot_quick + ['dpkg', '--print-architecture'],
+            stdout=subprocess.PIPE,
+        ).stdout.decode('ascii').strip()
+
     result = subprocess.run(
         in_chroot_quick + ['apt-cache', 'show'] + list(to_inspect),
         stdout=subprocess.PIPE,
@@ -212,6 +224,18 @@ def main():
                 if want.binary_version != binary_stanza['Version']:
                     continue
 
+                if (
+                    want.architecture is not None
+                    and want.architecture != args.primary_architecture
+                    and binary_stanza.get('Multi-Arch', 'no') != 'same'
+                ):
+                    logger.info(
+                        'Not installing %s: not Multi-Arch: same even '
+                        'though the library is',
+                        want.qualified_dbgsym_package,
+                    )
+                    continue
+
                 logger.info(
                     'Installing -dbgsym package: %s_%s',
                     want.qualified_dbgsym_package,

flatdeb/debos-runtimes.yaml

 {{- $apt_debug := or .apt_debug false -}}
 {{- $architecture := or .architecture "amd64" -}}
+{{- $foreignarchs := or .foreignarchs "" -}}
 {{- $suite := or .suite "stretch" -}}
 {{- $flatpak_arch := or .flatpak_arch $architecture -}}
 {{- $packages := or .packages "" -}}

run.py

@@ -1045,6 +1045,9 @@ class Builder:
                     '--artifactdir={}'.format(self.build_area),
                     '--scratchsize=8G',
                     '-t', 'architecture:{}'.format(self.primary_dpkg_arch),
+                    '-t', 'foreignarchs:{}'.format(
+                        ' '.join(self.dpkg_archs[1:]),
+                    ),
                     '-t', 'flatpak_arch:{}'.format(self.flatpak_arch),
                     '-t', 'suite:{}'.format(self.apt_suite),
                     '-t', 'ospack:{}'.format(tarball),