pbuilder: use an ExitStack

Doing so bears three advantages:
 * Adding more context managers - especially conditional ones - becomes
   easier.
 * Context managers can be delayed until the point where they're
   actually needed without adding to indentation.
 * We get rid of two local variables. Less state in your head.

1 files changed, 6 insertions, 3 deletions

diff --git a/mdbp/pbuilder.py b/mdbp/pbuilder.py
index fb5c4fe..052dce8 100644
--- a/mdbp/pbuilder.py
+++ b/mdbp/pbuilder.py
@@ -3,6 +3,7 @@
 """mdbp backend using pbuilder"""
 
 import argparse
+import contextlib
 import os
 import pathlib
 import shlex
@@ -78,8 +79,9 @@ def main() -> None:
     if not enablelog:
         cmd.extend(["--loglevel", "E"])
     apt_get = ["apt-get", "-oAPT::Keep-Downloaded-Path=false", "--yes"]
-    with tempfile.TemporaryDirectory() as hookdirn, get_dsc(build) as dscpath:
-        hookdir = pathlib.Path(hookdirn)
+    with contextlib.ExitStack() as stack:
+        hookdir = pathlib.Path(
+            stack.enter_context(tempfile.TemporaryDirectory()))
         hook = hookdir / "D50aptupdate"
         hook.write_text("""#/bin/sh
 set -e
@@ -95,7 +97,8 @@ set -e
 runuser -u pbuilder -- lintian %s "${BUILDDIR:-/tmp/buildd}"/*.changes
 """ % (shlex.join(apt_get), shlex.join(build["lintian"].get("options", []))))
             hook.chmod(0o755)
-        cmd.extend(["--hookdir", hookdirn, *args.pbuilderopts, str(dscpath)])
+        cmd.extend(["--hookdir", str(hookdir), *args.pbuilderopts,
+                    str(stack.enter_context(get_dsc(build)))])
         ret = subprocess.call(cmd, env=compute_env(build),
                               stdout=None if enablelog
                                      else subprocess.DEVNULL,