github: use last tag if no release found

Most projects do not use the "release" proprietary feature of Github, but plain old git tags instead. If no release is found in the repository, we try to use the latest release instead.

pypi2deb/github.py

@@ -26,6 +26,7 @@ from os.path import join, exists
 
 import aiohttp
 from github import Github
+from github.GithubException import UnknownObjectException
 
 
 @asyncio.coroutine
@@ -36,16 +37,20 @@ def github_download(name, github_url, version=None, destdir='.'):
     if not name:
         name = repo.name
 
-    latest_release = repo.get_latest_release()
+    try:
+        tag_name = repo.get_latest_release().tag_name
+    except UnknownObjectException:
+        # Some projects do not use Github Releases, check the latest tag instead
+        tag_name = repo.get_tags()[0].name
 
     if not version:
         # TODO: are there other special cases? vx.y.z tag gets rewritten as x.y.z
-        version = latest_release.tag_name.lstrip('v')
+        version = tag_name.lstrip('v')
 
     # cant use this for now, chk https://github.com/PyGithub/PyGithub/issues/1871
     # download_url = latest_release.tarball_url
     # so let's "forge" the right URL here
-    download_url = f"{github_url}/archive/{latest_release.tag_name}.tar.gz"
+    download_url = f"{github_url}/archive/{tag_name}.tar.gz"
 
     fname = f'{name}_{version}.orig.tar.gz'