Merge ~smoser/curtin:fix/curtainer-fix-for-trusty-dpkg-dev into curtin:master

[Scott Moser]

tools: fix curtainer --source with trusty.

Older version of dpkg-parsechangelog in trusty does not seem to
support '--file=<file>' correctly. It does seem to support
--file <file> though. So we'll just use that format.

see commit message

[Ryan Harper (raharper)]

Gnarly! Do we have a way to test this on jenkins prior to committing?

review: Approve

[Scott Moser (smoser)]

we can't really test on jenkins, or dont really need to.
the point of curtainer is that that all happens in a container.

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:922eb33a4581b984482061c6465e80435abc033a
https://jenkins.ubuntu.com/server/job/curtin-ci/813/
Executed test runs:
    SUCCESS: https://jenkins.ubuntu.com/server/job/curtin-ci/nodes=metal-amd64/813
    SUCCESS: https://jenkins.ubuntu.com/server/job/curtin-ci/nodes=metal-arm64/813
    SUCCESS: https://jenkins.ubuntu.com/server/job/curtin-ci/nodes=metal-ppc64el/813
    SUCCESS: https://jenkins.ubuntu.com/server/job/curtin-ci/nodes=metal-s390x/813

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/curtin-ci/813/rebuild

review: Approve (continuous-integration)

diff --git a/tools/curtainer b/tools/curtainer
index 3aa71df..525a998 100755
--- a/tools/curtainer
+++ b/tools/curtainer
@@ -186,8 +186,9 @@ main() {
         inside "$name" tar -C "$isrcd" -cf - . |
             tar -C "$getsource" -xf - ||
             fail "failed to copy source out to $getsource"
+        # 14.04 cannot take --file=<file>. Has to be 2 arguments.
         src_ver=$(inside "$name" dpkg-parsechangelog \
-            "--file=$isrcd/debian/changelog" "--show-field=version")
+            "--file" "$isrcd/debian/changelog" "--show-field=version")
         if [ "$src_ver" != "$pkg_ver" ]; then
             fail "source version ($src_ver) != package version ($pkg_ver)"
         fi