LSP: DSLX_PATH stopped working

[hzeller]

The DSLX_PATH environment variable used to be the way to tell he language server what the base path is for finding import paths.

Let's assume the XLS checkout is in a subdirectory of my homedir: /home/myhomedir/src/xls and thelanguage server configured for the editor.

Now opening a DSLX file. To make sure the language server finds all import paths, I am setting the DSLX_PATH to the root of the directory:

DSLX_PATH=/home/myhomedir/src/xls emacs src/xls/xls/dslx/stdlib/float32.x

This now lets the language server crash while opening the file:

XLS testing language server
Path configuration:
        stdlib=xls/dslx/stdlib
        dslx_path=/home/myhomedir/src/xls
        cwd=/home/myhomedir/src/xls
F1119 11:00:35.471252 1009793 language_server_adapter.cc:232] Check failed: absl::StartsWith(importer_filename, "file://") || absl::StartsWith(importer_filename, "memfile://") importer_filename: xls/dslx/stdlib/apfloat.x imported: "xls/dslx/stdlib/std.x"

It looks like some part of the code assumes regular host filenames, while others assume the file:// URI notation, which then clashes here.

[hzeller]

Looks like this broke with the introduction of the virtual filesystem in 1b175c6
Maybe @cdleary sees immediately what is amiss.