build_release: Fail GitHub uploads early

scripts/dev/build_release.py

@@ -292,6 +292,13 @@ def build_sdist():
     return artifacts
 
 
+def read_github_token():
+    """Read the GitHub API token from disk."""
+    token_file = os.path.join(os.path.expanduser('~'), '.gh_token')
+    with open(token_file, encoding='ascii') as f:
+        token = f.read().strip()
+
+
 def github_upload(artifacts, tag):
     """Upload the given artifacts to GitHub.
 
@@ -302,9 +309,7 @@ def github_upload(artifacts, tag):
     import github3
     utils.print_title("Uploading to github...")
 
-    token_file = os.path.join(os.path.expanduser('~'), '.gh_token')
-    with open(token_file, encoding='ascii') as f:
-        token = f.read().strip()
+    token = read_github_token()
     gh = github3.login(token=token)
     repo = gh.repository('qutebrowser', 'qutebrowser')
 
@@ -341,6 +346,12 @@ def main():
 
     upload_to_pypi = False
 
+    if args.upload is not None:
+        # Fail early when trying to upload without github3 installed
+        # or without API token
+        import github3
+        read_github_token()
+
     if os.name == 'nt':
         if sys.maxsize > 2**32:
             # WORKAROUND