[PATCH v4 5/6] patman: fail early in Setup when provided config file does not exist

[Maxim Cournoyer]

Rationale: if the user explicitly provide this argument, they probably
intend for it to be used.

Signed-off-by: Maxim Cournoyer <maxim.cournoyer at savoirfairelinux.com>
---

(no changes since v1)

 tools/patman/settings.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/patman/settings.py b/tools/patman/settings.py
index 8b846799df..c05efd2475 100644
--- a/tools/patman/settings.py
+++ b/tools/patman/settings.py
@@ -340,12 +340,16 @@ def Setup(parser, project_name, config_fname=None):
         parser:         The parser to update.
         project_name:   Name of project that we're working on; we'll look
             for sections named "project_section" as well.
-        config_fname:   Config filename to read.
+        config_fname:   Config filename to read.  An error is raised if it
+            does not exist.
     """
     # First read the git alias file if available
     _ReadAliasFile('doc/git-mailrc')
     config = _ProjectConfigParser(project_name)
 
+    if config_fname and not os.path.exists(config_fname):
+        raise Exception(f'provided {config_fname} does not exist')
+
     if not config_fname:
         config_fname = '%s/.patman' % os.getenv('HOME')
 
-- 
2.38.1