dev/chain_build.py: fix collapse_features() not working when no section present

diff --git a/dev/chain_build.py b/dev/chain_build.py
index fd1ded05b1c457fb8ee28ed6d05fac7a99837870..f4c9c835f7d92fcd027fb8593f1cf8648c143267 100755 (executable)
--- a/dev/chain_build.py
+++ b/dev/chain_build.py
@@ -95,9 +95,10 @@ def collapse_features(crate: str):
        f = open(join('src', _todash(crate), 'debian', 'debcargo.toml'), 'r+')
        toml = f.read()
        if COLL_LINE not in toml:
-               # below is to avoid inserting at end ending up in [some.directive]
+               _print('writing collapse_features for', crate)
                lines = toml.split('\n')
                for i, line in enumerate(lines):
+                       # avoid inserting at end ending up in [some.directive]
                        if line.startswith('['): #] to work around auto indent in my nvim
                                lines.insert(i, COLL_LINE)
                                lines.insert(i + 1, '')
@@ -105,6 +106,10 @@ def collapse_features(crate: str):
                                f.write('\n'.join(lines))
                                f.close()
                                return True
+               f.write('\n')
+               f.write(COLL_LINE)
+               f.close()
+               return True
 
 
 def build_one(crate: str, ver: str | None, prev_debs: list[str]):