pbuilder: uninline a function for locating the base.tgz

1 files changed, 13 insertions, 12 deletions

diff --git a/mdbp/pbuilder.py b/mdbp/pbuilder.py
index f1c48e3..1394034 100644
--- a/mdbp/pbuilder.py
+++ b/mdbp/pbuilder.py
@@ -10,11 +10,23 @@ import shlex
 import subprocess
 import sys
 import tempfile
+import typing
 
 from .common import AddSpaceSeparatedValues, buildjson, clean_dir, \
         compute_env, get_dsc, make_option, profile_option, \
         temporary_static_file
 
+def find_basetgz(distribution: str,
+                 basedir: str = "/var/cache/pbuiler") -> typing.Optional[str]:
+    """Locate a pbuilder base.tgz for the given distribution."""
+    if distribution in ("sid", "unstable"):
+        return None
+    for pat in ("/%s-base.tgz", "/%s.tgz"):
+        basetgz = basedir + pat % distribution
+        if pathlib.Path(basetgz).is_file():
+            return basetgz
+    raise ValueError("unsupported distribution %s" % distribution)
+
 def main() -> None:
     """Entry point for mdbp-pbuilder backend"""
     parser = argparse.ArgumentParser()
@@ -45,24 +57,13 @@ def main() -> None:
     if "bd-uninstallable-explainer" in build:
         raise ValueError("bd-uninstallable-explainer %r not supported" %
                          build["bd-uinstallable-explainer"])
-    if build["distribution"] in ("sid", "unstable"):
-        basetgz = None
-    else:
-        for pat in ("/var/cache/pbuilder/%s-base.tgz",
-                    "/var/cache/pbuidler/%s.tgz"):
-            basetgz = pat % build["distribution"]
-            if pathlib.Path(basetgz).is_file():
-                break
-        else:
-            raise ValueError("unsupported distribution %s" %
-                             build["distribution"])
 
     cmd = [
         *([] if os.getuid() == 0 else ["sudo", "-E", "--"]),
         "/usr/sbin/pbuilder",
         "build",
         "--no-source-only-changes",
-        *make_option("--basetgz", basetgz),
+        *make_option("--basetgz", find_basetgz(build["distribution"])),
         *make_option("--architecture", build.get("build_architecture")),
         *make_option("--host-arch", build.get("host_architecture")),
         *make_option("--othermirror",