Tempfiles exported for use by a lua script (e.g. `hugin`) disappear immediately after export

[charludo]

Steps to reproduce:

1. enable contrib/hugin script, and ensure paths are configured correctly and hugin is installed
2. select images you want to stitch into a panorama
3. in export dialog, select "hugin panorama" as "target storage"
4. select file format (e.g. TIFF)
5. (optionally, makes no difference) tick "launch hugin gui"
6. run inotifywait -m /tmp -e create --format '%w%f' | while read f; echo "$f"; end (or similar) in terminal
7. press "start export"
8. wait for export to finish, see toast message "launching hugin"
9. nothing happens
10. check inotify and see that all images were created at one point (i.e. one log line per image in the form of /tmp/DSCF0721.tif)
11. check dartable log and see:

    sh: line 1: '/path/to/hugin' '/tmp/DSCF0720.tif' '/tmp/DSCF0713.tif' '/tmp/DSCF0721.tif' '/tmp/DSCF0715.tif' '/tmp/DSCF0718.tif' '/tmp/DSCF0717.tif' '/tmp/DSCF0716.tif' '/tmp/DSCF0714.tif' '/tmp/DSCF0719.tif' : No such file or directory
    

12. note: /path/to/hugin DOES exist and is the hugin executable
13. ls /tmp shows images are gone

I assume they somehow get cleaned from /tmp after the darktable export process (?) exits and the files are essentially orphaned.

[wpferguson]

How is darktable installed? Is it a flatpak or a snap package? If so, scripts that call external executables wont work because of the sandbox environment.

The script does clean up after itself, so /tmp files are deleted when it finishes.

[charludo]

Hi, thanks for the quick response. Darktable is installed through the nix package manager, on NixOS. I have added the following to my config:

lua/executable_paths/hugin=~/.nix-profile/bin/hugin
lua/executable_paths/hugin_executor=~/.nix-profile/bin/hugin_executor
lua/executable_paths/pto_gen=~/.nix-profile/bin/pto_gen
lua/script_manager/tools/executable_manager=TRUE

and also picked the binaries manually through the executable manager, without effect.

But what I reading from your comment is that you think it likely that the error message does pertain to the binary, not the images, and that the images disappearing is expected in this case?

[charludo]

Thought maybe the reason might be that those are symlinks, but not so:

lua/executable_paths/hugin=${lib.getExe' pkgs.hugin "hugin"}
lua/executable_paths/hugin_executor=${lib.getExe' pkgs.hugin "hugin_executor"}
lua/executable_paths/pto_gen=${lib.getExe' pkgs.hugin "pto_gen"}

results in the same error:

sh: line 1: '/nix/store/w5q8fm5q12g5c4lkrrfjjac49236jrmd-hugin-2025.0.1/bin/hugin' '/tmp/DSCF0713.tif' '/tmp/DSCF0719.tif' '/tmp/DSCF0720.tif' '/tmp/DSCF0715.tif' '/tmp/DSCF0714.tif' '/tmp/DSCF0718.tif' '/tmp/DSCF0721.tif' '/tmp/DSCF0716.tif' '/tmp/DSCF0717.tif' : No such file or directory

[wpferguson]

I asked the resident NixOS expert to have a look...