After #2848 (cc @tcl3), tests with variants like html/syntax/parsing/html5lib_tests2.html will be listed by list-tests with the paths:

/html/syntax/parsing/html5lib_tests2.html?run_type=uri
/html/syntax/parsing/html5lib_tests2.html?run_type=write
/html/syntax/parsing/html5lib_tests2.html?run_type=write_single

Because list-tests is now used before calling import-wpt-test.py, this means that the ?run_type=uri gets passed along to that script as well, so the files created are:

Tests/LibWeb/Text/input/wpt-import/html/syntax/parsing/html5lib_tests2.html?run_type=uri
Tests/LibWeb/Text/input/wpt-import/html/syntax/parsing/html5lib_tests2.html?run_type=write
Tests/LibWeb/Text/input/wpt-import/html/syntax/parsing/html5lib_tests2.html?run_type=write_single

(the ?run_type=uri, etc are part of the filenames)

The import then fails when trying to run the tests:

Importing test from /html/syntax/parsing/html5lib_tests2.html?run_type=uri
 114633 Lost connection to RequestServer
Runtime error: No tests found matching filter
Importing test from /html/syntax/parsing/html5lib_tests2.html?run_type=write
 114783 Lost connection to RequestServer
Runtime error: No tests found matching filter
Importing test from /html/syntax/parsing/html5lib_tests2.html?run_type=write_single
 114868 Lost connection to RequestServer
Runtime error: No tests found matching filter

I believe query parameters should be stripped before passing the path to import-wpt-test.py, or something to that effect.