Bug: FreeSurfer launch may fail due to an extra license added by License Finder module (renamed)

[MontrealSergiy]

User report from the internal CBRAIN chat on July 7, 2026:

When I try to launch FS 8.1, I get:
"This task requires 2 mandatory file(s) and 0 optional file(s)"

NIFTI file (required)
License file (required)

This happens despite having selected both the file list and the license.txt file. Same when selecting a Nifti and license.txt

PS. At the moment I suspect the user provided license file was registered as a text file. Which is default type on upload, and seems allowed in FS boutiques descriptor . As workaround I suggested skip license file during submission, which helped. User suggests it still might help to provide more helpful error message, so user can correct situation himself without need to reach out CBRAIN team.

[MontrealSergiy]

Perhaps it is better give more detailed error message at launch, something along the lines

--- a/lib/boutiques_freesurfer_license_finder.rb
+++ b/lib/boutiques_freesurfer_license_finder.rb
@@ -60,6 +60,14 @@ module BoutiquesFreesurferLicenseFinder
       .order("updated_at desc")
       .first
 
+    if !lic.present? && params[:interface_userfile_ids].size > 1
+      txt_lic = TextFile
+            .where(:user_id => self.user_id, :id => params[:interface_userfile_ids], :name => "license.txt")
+            .order("updated_at desc")
+            .first
+      cb_error("It seems your `license.txt` file is registered/uploaded as Text File, please change type to FreeSurfer License. Or provide another file of FreeSurfer License type" ) if txt_lic.present?    # the second part of the message targets unlikely but possible case of case for hypothetical tool that takes two licenses
+    end
+
     # Find a license among all files owned by the user
     lic ||= FreesurferLicense
       .where(:user_id => self.user_id)

Another alternative BoutiquesFreesurferLicenseFinder module could just consider license.txt valid license even if type unassigned? Perhaps after peeking into file content.

Note 1. Launch fails not due to file checking, but file count: FS type check module allows for licenses of Text File type.

Note 2. We can address or at the least alleviate the problem on the level of cbrain-plugins-neuro repo, although I can thinks on more sophisticated solutions involving main repo

[MontrealSergiy]

I submitted a PR to address to neuro plugins repo. Perhaps, also by default set license.txt file default type to FS License?

[MontrealSergiy]

Pierre closed the PR with the main argument that the module is "for convenience only" and therefore should not display error messages. In other words, if it cannot assign a license, it should simply do nothing.

The PR could be easily adjusted to follow that approach, without producing any warnings or messages, should I resubmit?

Although the original request was to improve the error message that users see, this is already an improvement. Whenever we arrive with other, better idea, no one stop us to add FS license validation or warning module, method or conditional somewhere else.