FortLS (language server) unable to find Fortran modules when run in QTCreator

I’m running QTCreator 17.0.0 under MSYS2, trying to get the FortLS (fortran language server) running as a custom language server – to help with working on some Fortran 90 source code.

I installed FortLS via pip, and it is version 3.2.2.

I have attempted to configure QTCreator to use FortLS via the following:

As you can see, I’ve passed the --config option to point it to a specific .fortlsrc file with its JSON-formatted configuration settings.

That configuration is just all the default values, with the exception of the source_dirs part:

{
   "nthreads": 4,
   "notify_init": false,
   "incremental_sync": false,
   "recursion_limit": 1000,
   "sort_keywords": false,
   "disable_autoupdate": false,
   "debug_log": false,

   "source_dirs": ["/c/source/myproject/module_a", "/c/source/myproject/module_b"],
   "incl_suffixes": [],
   "excl_suffixes": [],
   "excl_paths": [],

   "autocomplete_no_prefix": false,
   "autocomplete_no_snippets": false,
   "autocomplete_name_only": false,
   "lowercase_intrinsics": false,
   "use_signature_help": false,

   "hover_signature": false,
   "hover_language": "fortran90",

   "max_line_length": -1,
   "max_comment_line_length": -1,
   "disable_diagnostics": false,

   "pp_suffixes": [],
   "include_dirs": [],
   "pp_defs": {},

   "symbol_skip_mem": false,

   "enable_code_actions": false
}

I know that source_dirs isn’t recursive, which is fine. Both of those source directories are flat.

This all works, but the results are lackluster. All I get when looking at my Fortran source files is a big pile of Module "name" not found in project. I am not certain why. It should be able to find them given I pointed to all the source directories with source_dirs, so why can’t it find them?

No other features of FortLS seem to be working. No highlighting, no auto-completion, nada. I’d assume this is because it’s hung up on the modules – but I’m not sure. Maybe QTCreator’s generic language server support just isn’t rich enough to support FortLS?

I did attempt enabling the debug_log, but the output doesn’t seem to tell me much. It acts as if it’s running normally and only noticed the missing modules.