mkWindowsApp - fileMap only works if the base name of both components is the same

[Niols]

In some cases, fileMap only works if the base name of both components is the same. For instance, if the map looks like:

fileMap = {
  "$HOME/.config/A" = "drive_c/users/$USER/AppData/Roaming/B";
};

and B is a directory, then loading A into the temporary Wine directory B works fine (and, the very first time, does nothing). However, persisting B into A does not work and the files will be persisted to $HOME/.config/B instead. The culprit is the function persist_file:

https://github.com/emmanuelrosa/erosanix/blob/90f5e8e345d940d74cad215b0b59eb2f83682383/pkgs/mkwindowsapp/default.nix#L189-L206

When the source $s is a directory (line 202), then we run cp -v -r -n "$s" "$base_dir", where base_dir=$(dirname "$d"). In the example:

$s == "$WINEPREFIX/drive_c/users/$USER/AppData/Roaming/B"
$d == "$HOME/.config/A"
$base_dir == "$HOME/.config/"

so we run:

cp -v -r -n "$WINEPREFIX/drive_c/users/$USER/AppData/Roaming/B" "$HOME/.config/"

which indeed creates $HOME/.config/B instead of $HOME/.config/A.

A mitigation is of course to ensure A == B, and this is what I use for now.

Thank you for this app, by the way — it's amazing!

[emmanuelrosa]

You're welcome! I hope you find it useful.

I've known about this issue for a while, but I haven't found a solution. I use the same work-around ;)

The only way I've been able to address this is with a reimplementation of the mapping code. I believe I used rsync. I probably still have that code in a branch, but I've been hesitant to merge it, even after writing unit tests.

I'll have to revisit this.

[Niols]

If you bring back this code, I'll happily have another look myself. I am not an rsync expert but it does look like the right tool for a job like this. I could otherwise suggest a modification to the current mapping code that should do it, but that would be yet again more code, and I'm not sure that this is the right way to proceed.

[emmanuelrosa]

Fixed in 87641eed8d937b196d33a87bcde05ec4f2d3025f

[Niols]

Indeed, looks great!