Prevent merge from crashing with a WindowsPath serialization error

[lstein]

What type of PR is this? (check all applicable)

• Bug Fix

Have you discussed this change with the InvokeAI team?

• Yes

Have you updated all relevant documentation?

• Yes

Description

On Windows systems, model merging was crashing at the very last step with an error related to not being able to serialize a WindowsPath object. I have converted the path that is passed to save_pretrained into a string, which I believe will solve the problem.

Note that I had to rebuild the web frontend and add it to the PR in order to test on my Windows VM which does not have the full node stack installed due to space limitations.

Related Tickets & Documents

https://discord.com/channels/1020123559063990373/1042475531079262378/1140680788954861698

[blessedcoolant]

Wont this resolved by just passing dump_path.as_posix() to save_pretrained instead of doing the whole string conversion everywhere else?

[lstein]

Oooh, I didn't know about as_posix() ! I'd been looking for the method that turns paths into strings, but the name must have thrown me.

There are actually two places where paths need to be turned into strings, one just before save_pretrained() and the other where the paths to the models to be merged are passed to the merge pipeline.

I'll go back and restore the call signatures to the way they were, then use as_posix() before passing the paths to the merge code.