Problem Running in Neovim on Windows with Git BASH

[eignnx]

I can't get the plugin to run on in Neovim. I'm not sure if me using Window's Git BASH instead of WSL is fundamentally a terrible idea, but here we are.

My system:

$ nvim --version; swipl --version; sh --version
NVIM v0.11.0
Build type: Release
LuaJIT 2.1.1741730670

SWI-Prolog version 9.0.4 for x64-win64

GNU bash, version 5.2.15(1)-release (x86_64-pc-msys)

I followed the instructions under Native LSP (for Neovim >= 0.11) (as of writing this, there seems to be a typo at the end of this section: vim.ls.enable({'prolog'}) ought to be vim.lsp.enable({'prolog'}))

After restarting Neovim and opening a Prolog file I got this message:

Client prolog quit with exit code 2 and signal 0. Check log for errors: C:/Users/REDACTED/AppData/Local/nvim-data/lsp.log

The log file contents:

[START][2025-05-20 14:47:13] LSP logging initiated
[ERROR][2025-05-20 14:47:13] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"Warning: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:\r\nWarning:    import/1: prolog_help:help_html/3 is not exported (still imported into lsp_utils)\r\n"
[ERROR][2025-05-20 14:47:13] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"Warning: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:\r\nWarning:    import/1: prolog_help:help_objects/3 is not exported (still imported into lsp_utils)\r\n"
[ERROR][2025-05-20 14:47:13] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:13:\r\nERROR:    source_sink `library(macros)' does not exist\r\n"
[ERROR][2025-05-20 14:47:13] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"Warning: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:13:\r\nWarning:    Goal (directive) failed: lsp_formatter:use_module(library(macros))\r\n"
[ERROR][2025-05-20 14:47:13] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:63:1: Syntax error: Operator expected\r\n"
[ERROR][2025-05-20 14:47:13] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:170:22: Syntax error: Operator expected\r\n"
[ERROR][2025-05-20 14:47:13] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:253:20: Syntax error: Operator expected\r\n"
[ERROR][2025-05-20 14:47:13] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"% Starting stdio client\r\n"
[ERROR][2025-05-20 14:47:13] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: -g lsp_server:main: Domain error: `waitable_stream' expected, found `user_input'\r\nERROR: In:\r\nERROR:   [15] wait_for_input([user_input],_182,infinite)\r\nERROR:   [14] lsp_server:client_handler(_234-_236,user_input,user_output) at c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl:101\r\nERROR:    [9] catch(lsp_server:main,error(domain_error(waitable_stream,user_input),context(...,_294)),'$toplevel':true) at c:/program files/swipl/boot/init.pl:565\r\nERROR:    [8] catch_with_backtrace(lsp_server:main,error(domain_error(waitable_stream,user_input),context(...,_358)),'$toplevel':true) at c:/program files/swipl/boot/init.pl:645\r\nERROR: \r\nERROR: Note: some frames are missing due to last-call optimization.\r\nERROR: Re-run your program in debug mode (:- debug.) to get more detail.\r\n"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"Warning: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:\r\nWarning:    import/1: prolog_help:help_html/3 is not exported (still imported into lsp_utils)\r\n"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"Warning: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:\r\nWarning:    import/1: prolog_help:help_objects/3 is not exported (still imported into lsp_utils)\r\n"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:13:\r\nERROR:    source_sink `library(macros)' does not exist\r\n"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"Warning: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:13:\r\nWarning:    Goal (directive) failed: lsp_formatter:use_module(library(macros))\r\n"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:63:1: Syntax error: Operator expected\r\n"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:170:22: Syntax error: Operator expected\r\n"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:253:20: Syntax error: Operator expected\r\n"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"% Starting stdio client\r\n"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"ERROR: -g lsp_server:main: Domain error: `waitable_stream' expected, found `user_input'\r\nERROR: In:\r\nERROR:   [15] wait_for_input([user_input],_182,infinite)\r\nERROR:   [14] lsp_server:client_handler(_234-_236,user_input,user_output) at c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl:101\r\nERROR:    [9] catch(lsp_server:main,error(domain_error(waitable_stream,user_input),context(...,_294)),'$toplevel':true) at c:/program files/swipl/boot/init.pl:565\r\nERROR:    [8] catch_with_backt"
[ERROR][2025-05-20 14:55:20] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"race(lsp_server:main,error(domain_error(waitable_stream,user_input),context(...,_358)),'$toplevel':true) at c:/program files/swipl/boot/init.pl:645\r\nERROR: \r\nERROR: Note: some frames are missing due to last-call optimization.\r\nERROR: Re-run your program in debug mode (:- debug.) to get more detail.\r\n"

If I try running the lsp start command from the shell directly I get this error:

$ swipl -g 'use_module(library(lsp_server))' -g lsp_server:main -t halt -- stdio
Warning: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:
Warning:    import/1: prolog_help:help_html/3 is not exported (still imported into lsp_utils)
Warning: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:
Warning:    import/1: prolog_help:help_objects/3 is not exported (still imported into lsp_utils)
ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:13:
ERROR:    source_sink `library(macros)' does not exist
Warning: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:13:
Warning:    Goal (directive) failed: lsp_formatter:use_module(library(macros))
ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:63:1: Syntax error: Operator expected
ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:170:22: Syntax error: Operator expected
ERROR: c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:253:20: Syntax error: Operator expected
% Starting stdio client
ERROR: -g lsp_server:main: No permission to encoding stream `user_input'
ERROR: In:
ERROR:   [14] set_stream(user_input,encoding(octet))
ERROR:   [13] lsp_server:handle_requests_stream(<stream>(00007ff811b54560,00007ff811b54660)) at c:/users/REDACTED/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl:96
ERROR:    [9] catch(lsp_server:main,error(permission_error(encoding,stream,user_input),context(...,_286)),'$toplevel':true) at c:/program files/swipl/boot/init.pl:565
ERROR:    [8] catch_with_backtrace(lsp_server:main,error(permission_error(encoding,stream,user_input),context(...,_352)),'$toplevel':true) at c:/program files/swipl/boot/init.pl:645
ERROR:
ERROR: Note: some frames are missing due to last-call optimization.
ERROR: Re-run your program in debug mode (:- debug.) to get more detail.

That error mentions a permission error so I re-ran the command in a new terminal window opened as Administrator and got the same result unfortunately.

[jamesnvc]

It looks like there's an error with loading library(macros), which was added to SWI relatively recently. Are you able to update swipl easily? It's easy enough for me to remove the dependency if it's particularly annoying, I'm only using it in one place for minor convenience.

Not sure about the encoding issue; that seems like it could be a Windows issue. If it persists after upgrading swipl I can continue to investigate (I think there may have been some changes to handling Windows stream encoding issues at some point after 9.0.4 as well).

Oh, and fixed the typo - thanks!

[eignnx]

Ok I updated to SWI 9.3.24, but I'm still running into the permission error when setting stream properties:

$ swipl -g 'use_module(library(lsp_server))' -g lsp_server:main -t halt -- stdio
ERROR: -g lsp_server:main: No permission to encoding stream `user_input'
ERROR: In:
ERROR:   [14] set_stream(user_input,encoding(octet))
ERROR:   [13] lsp_server:handle_requests_stream(<stream>(00007ff81d5d1660,00007ff81d5d1760)) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl:96
ERROR:    [9] catch(lsp_server:main,_210,'$toplevel':true) at c:/program files/swipl/boot/init.pl:565
ERROR:    [8] catch_with_backtrace(lsp_server:main,_256,'$toplevel':true) at c:/program files/swipl/boot/init.pl:645

Manually attempting to set encoding(octet) on user_input seems to be the problem:

1 ?- current_input(In), set_stream(In, encoding(octet)).
ERROR: No permission to encoding stream `<stream>(00007ff81d5d1660)'
ERROR: In:
ERROR:   [13] set_stream(<stream>(00007ff81d5d1660),encoding(octet))
ERROR:   [12] '<meta-call>'('<garbage_collected>') <foreign>
ERROR:   [11] toplevel_call('<garbage_collected>') at c:/program files/swipl/boot/toplevel.pl:1315

I found this post on the SWI forums talking about the same problem setting properties of user_input (the user was running Windows 7, I'm on Windows 10).

---

Update: I got the lsp running!

Instead of using stdin, I had the server run over a socket by changing my config:

return {
   cmd = { 'swipl',
           '-g', 'use_module(library(lsp_server))',
           '-g', 'lsp_server:main',
           '-t', 'halt',
           -- '--', 'stdio' },
           '--', 'port 9876' }, -- Use whatever port number you like
   root_markers = { '.git', },
   filetypes = { 'prolog' },
}

So it seems Windows just has problems settings stream properties of stdin/stdout, but can do it just fine for a socket connection!

[jamesnvc]

Excellent! Switching to the socket was going to be my next suggestion :) Is neovim able to connect automatically to a server started in that manner? If so, I'll certainly update the documentation - I was under the impression that neovim wasn't able to connect to an automatically started socket server.

[eignnx]

Hmm you seem to be right. I've been tinkering a bunch and haven't been able to get the lsp activated.

Running :checkhealth lsp from inside a .pl file gives:

==============================================================================
vim.lsp:                                     require("vim.lsp.health").check()

- LSP log level : WARN
- Log path: C:/Users/USER/AppData/Local/nvim-data/lsp.log
- Log size: 34 KB

vim.lsp: Active Clients ~
- No active clients

vim.lsp: Enabled Configurations ~
- prolog:
  - cmd: { "swipl", "-g", "use_module(library(lsp_server))", "-g", "lsp_server:main", "-t", "halt", "--", "port 9876" }
  - filetypes: pl, prolog, swiprolog
  - root_markers: .git


vim.lsp: File Watcher ~
- file watching "(workspace/didChangeWatchedFiles)" disabled on all clients

vim.lsp: Position Encodings ~
- No active clients

And lsp.log reads:

[ERROR][2025-05-22 12:48:14] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"Warning: c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:\r\nWarning:    import/1: prolog_help:help_html/3 is not exported (still imported into lsp_utils)\r\n"
[ERROR][2025-05-22 12:48:14] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"Warning: c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:\r\nWarning:    import/1: prolog_help:help_objects/3 is not exported (still imported into lsp_utils)\r\n"
[ERROR][2025-05-22 12:48:14] ...p/_transport.lua:36	"rpc"	"swipl"	"stderr"	"% Unknown args [port 9876]\r\n"

The first two lines in the above seem like warnings, the last line is talking about port 9876 being an unknown argument.

I'm wondering if there's a hacky bash script I could write that would use something like nc to bridge the gap and allow neovim to talk to the socket via stdin/stdout.

[jamesnvc]

The "low-hanging fruit" issue is, I think, that "port 9876" should be two arguments, like "port", "9876".

However, I think even if that works, vim will have issues, since it won't know that's the port to connect to! I think I saw something somewhere in the neovim docs about how to have it connect to an existing socket server though, which might be the way to go; I'll try to find that link.

[jamesnvc]

It looks like you can pass in the function vim.lsp.rpc.connect(host, port) instead of the command; this would require you to have started the server already externally though. A bit of a pain, but maybe automatable? So you could start the server in a terminal somewhere like

swipl -g 'use_module(library(lsp_server))' -g 'lsp_server:main' -t halt -- port 9876

then configure neovim like

return {
   cmd = vim.lsp.rpc.connect('127.0.0.1', 9876),
   root_markers = { '.git', },
   filetypes = { 'prolog' },
}

[eignnx]

Ok I tried that out and it looks promising. Neovim did connect to the server, but the server threw some errors. Here's the server's log output after opening a .pl document:

$ swipl -g 'use_module(library(lsp_server))' -g 'lsp_server:main' -t halt -- port 9876
Warning: c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:
Warning:    import/1: prolog_help:help_html/3 is not exported (still imported into lsp_utils)
Warning: c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:23:
Warning:    import/1: prolog_help:help_objects/3 is not exported (still imported into lsp_utils)
% Starting socket client on port 9876
% [Thread 3] Connecting new client ip(127,0,0,1)
% [Thread 3] initialized _124500{jsonrpc:2.0,method:initialized,params:_124484{}}
% [Thread 3] Failed checking errors
ERROR: [Thread 3] Domain error: `handleable_message' expected, found `_158756{body:_158768{id:2,jsonrpc:"2.0",method:"textDocument/semanticTokens/full",params:_158788{textDocument:_158796{uri:"file:///C:/Users/USER/prolog-lsp-bridge/test.pl"}}},headers:t("Content-Length","153",-,t,t)}' (handle_msg/3 returned false)
ERROR: [Thread 3] In:
ERROR: [Thread 3]   [16] throw(error(domain_error(handleable_message,...),context(_158872,"handle_msg/3 returned false")))
ERROR: [Thread 3]   [15] '<meta-call>'(lsp_server:(...,...)) <foreign>
ERROR: [Thread 3]   [14] catch(lsp_server:(...,...),_158952,lsp_server:(...,...)) at c:/program files/swipl/boot/init.pl:565
ERROR: [Thread 3]   [13] catch_with_backtrace(lsp_server:(...,...),_159010,lsp_server:(...,...)) at c:/program files/swipl/boot/init.pl:645

When I tried grn for symbol renaming I got:

ERROR: [Thread 3] source_sink `'/C:/Users/USER/prolog-lsp-bridge/test.pl'' does not exist (Invalid argument)
ERROR: [Thread 3] In:
ERROR: [Thread 3]   [23] open('/C:/Users/USER/prolog-lsp-bridge/test.pl',read,_932)
ERROR: [Thread 3]   [22] <meta call>
ERROR: [Thread 3]   [21] sig_atomic(lsp_reading_source:open('/C:/Users/USER/prolog-lsp-bridge/test.pl',read,_994)) <foreign>
ERROR: [Thread 3]   [20] setup_call_cleanup(lsp_reading_source:open('/C:/Users/USER/prolog-lsp-bridge/test.pl',read,_1042),lsp_reading_source:(repeat,...),lsp_reading_source:close(_1064)) at c:/program files/swipl/boot/init.pl:681
ERROR: [Thread 3]   [19] lsp_reading_source:file_lines_start_end('/C:/Users/USER/prolog-lsp-bridge/test.pl',_1102) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_reading_source.pl:37
ERROR: [Thread 3]   [18] lsp_highlights:highlights_at_position('/C:/Users/USER/prolog-lsp-bridge/test.pl',line_char(25,10),'$var'(_1154),_1144) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_highlights.pl:15
ERROR: [Thread 3]   [17] lsp_server:handle_msg("textDocument/rename",_1198{id:3,jsonrpc:"2.0",method:"textDocument/rename",params:_1218{newName:"emit_table_header2",position: ...,textDocument: ...}},_1234{id:3,result:_1240}) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl:289
ERROR: [Thread 3]   [16] '<meta-call>'(lsp_server:(...,...)) <foreign>
ERROR: [Thread 3]   [15] catch(lsp_server:(...,...),_1320,lsp_server:(...,...)) at c:/program files/swipl/boot/init.pl:565
ERROR: [Thread 3]   [14] catch_with_backtrace(lsp_server:(...,...),_1378,lsp_server:(...,...)) at c:/program files/swipl/boot/init.pl:645

ERROR: [Thread 3] source_sink '/C:/Users/USER/prolog-lsp-bridge/test.pl'' does not exist (Invalid argument)`

That kinda looks like there's a problem with path handling on Windows. These are the path variations that do and don't work on my system:

?- open('/C:/Users/USER/prolog-lsp-bridge/test.pl', read, S). % What lsp_server got confused by
ERROR: source_sink `'/C:/Users/USER/prolog-lsp-bridge/test.pl'' does not exist (Invalid argument)
?- open('/C/Users/USER/prolog-lsp-bridge/test.pl', read, S). % Variation without the colon
ERROR: source_sink `'/C/Users/USER/prolog-lsp-bridge/test.pl'' does not exist (No such file or directory)
?- open('/c/Users/USER/prolog-lsp-bridge/test.pl', read, S). % Lowercase drivename also doesn't work
ERROR: source_sink `'/c/Users/USER/prolog-lsp-bridge/test.pl'' does not exist (No such file or directory)
?- open('C:\\Users\\USER\\prolog-lsp-bridge\\test.pl', read, S). % Backslashes and no leading slash works
S = <stream>(00000203853bd9c0).

?- open('C:/Users/USER/prolog-lsp-bridge/test.pl', read, S). % Remove the leading slash and it works
S = <stream>(00000203853bd030).

?- open('c:/Users/USER/prolog-lsp-bridge/test.pl', read, S). % Lowercase drivename is also fine
S = <stream>(00000203853bd140).

[jamesnvc]

Great, thanks for figuring that out! I'll try to get a fix together for this soon 👍

[jamesnvc]

Just put out 3.11.0 that attempts to handle this case - can you try updating & see if that works?

[eignnx]

I updated to 3.11.0, but it looks like approximately the same error messages. Here's after opening a prolog file:

$ swipl -g 'use_module(library(lsp_server))' -g 'lsp_server:main' -t halt -- port 9876
Warning: c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:24:
Warning:    import/1: prolog_help:help_html/3 is not exported (still imported into lsp_utils)
Warning: c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl:24:
Warning:    import/1: prolog_help:help_objects/3 is not exported (still imported into lsp_utils)
% Starting socket client on port 9876
% [Thread 3] Connecting new client ip(127,0,0,1)
% [Thread 3] initialized _124518{jsonrpc:2.0,method:initialized,params:_124490{}}
% [Thread 3] Failed checking errors
ERROR: [Thread 3] Domain error: `handleable_message' expected, found `_480{body:_492{id:2,jsonrpc:"2.0",method:"textDocument/semanticTokens/full",params:_512{textDocument:_520{uri:"file:///C:/Users/USER/AppData/Local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl"}}},headers:t("Content-Length","189",-,t,t)}' (handle_msg/3 returned false)
ERROR: [Thread 3] In:
ERROR: [Thread 3]   [18] throw(error(domain_error(handleable_message,...),context(_596,"handle_msg/3 returned false")))
ERROR: [Thread 3]   [17] '<meta-call>'(lsp_server:(...,...)) <foreign>
ERROR: [Thread 3]   [16] catch(lsp_server:(...,...),_676,lsp_server:(...,...)) at c:/program files/swipl/boot/init.pl:565
ERROR: [Thread 3]   [15] catch_with_backtrace(lsp_server:(...,...),_734,lsp_server:(...,...)) at c:/program files/swipl/boot/init.pl:645

And here's after attempting grn renaming:

ERROR: [Thread 3] source_sink `'/C:/Users/USER/AppData/Local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl'' does not exist (Invalid argument)
ERROR: [Thread 3] In:
ERROR: [Thread 3]   [25] open('/C:/Users/USER/AppData/Local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl',read,_942)
ERROR: [Thread 3]   [24] <meta call>
ERROR: [Thread 3]   [23] sig_atomic(lsp_reading_source:open('/C:/Users/USER/AppData/Local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl',read,_1004)) <foreign>
ERROR: [Thread 3]   [22] setup_call_cleanup(lsp_reading_source:open('/C:/Users/USER/AppData/Local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl',read,_1052),lsp_reading_source:(repeat,...),lsp_reading_source:close(_1074)) at c:/program files/swipl/boot/init.pl:681
ERROR: [Thread 3]   [21] lsp_reading_source:file_lines_start_end('/C:/Users/USER/AppData/Local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl',_1112) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_reading_source.pl:37
ERROR: [Thread 3]   [20] lsp_highlights:highlights_at_position('/C:/Users/USER/AppData/Local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl',line_char(72,12),'$var'(_1164),_1154) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_highlights.pl:15
ERROR: [Thread 3]   [19] lsp_server:handle_msg("textDocument/rename",_1208{id:3,jsonrpc:"2.0",method:"textDocument/rename",params:_1228{newName:"dispatch_socket_client2",position: ...,textDocument: ...}},_1244{id:3,result:_1250}) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl:289
ERROR: [Thread 3]   [18] '<meta-call>'(lsp_server:(...,...)) <foreign>
ERROR: [Thread 3]   [17] catch(lsp_server:(...,...),_1330,lsp_server:(...,...)) at c:/program files/swipl/boot/init.pl:565
ERROR: [Thread 3]   [16] catch_with_backtrace(lsp_server:(...,...),_1388,lsp_server:(...,...)) at c:/program files/swipl/boot/init.pl:645

Looking over your 2nd most recent commit, these clauses seem incorrect. On Windows we'd want one less / instead of one more, right?

url_path(Url, Path) :-
    current_prolog_flag(windows, true),
    atom_concat('file:///', Path, Url), !.
url_path(Url, Path) :-
    atom_concat('file://', Path, Url).

Although when I changed the 3rd line to atom_concat('file:/', Path, Url), !. it didn't seem to solve the problem either. I went on to try find/replacing all atom_concat('file://', with url_path( in prolog/lsp_server.pl, but still ran into issues.

I think neovim must be sending paths formatted like file:///C:/... to the language server, and there may need to be a parsing step before prolog can open a path like that on Windows.

An example of the error I see after modifying lsp_utils.pl and lsp_server.pl:

ERROR: [Thread 3]   [93] open('file:/file:///C:/Users/USER/AppData/Local/swi-prolog/pack/lsp_server/prolog/lsp_utils.pl',read,_902)

In that case, I'm even seeing file:/file:///C:/... which definitely seems wrong.

[jamesnvc]

Looking over your 2nd most recent commit, these clauses seem incorrect. On Windows we'd want one less / instead of one more, right?

Right; atom_concat/3 is being called in mode (+,-,+) here, so that should be stripping and additional slash off.

Oh! I just realized I made the change in lsp_server too, but forgot to commit that file! That’s what I get for trying to finish something before rushing out the door 😅. I’ll push shortly.

(The reason just replacing in the file didn’t work is because the order of arguments is switched)

[jamesnvc]

Can you try 3.11.1? Sorry about that!

[eignnx]

Ah I wasn't thinking about modes! That makes sense, thanks for explaining 🙏🏻

So with 3.11.1 I seem to be closer than ever, but still hitting a few issues.

What's Working

• It looks like semantic highlighting is working!
• :checkhealth lsp shows that there's an active client, which is new:

  vim.lsp: Active Clients ~
  - prolog (id: 1)
    - Version: ? (no serverInfo.version response)
    - Root directory: nil
    - Command: <function @C:\Program Files\Neovim\share\nvim\runtime/lua/vim/lsp/rpc.lua:626>
    - Settings: {}
    - Attached buffers: 1
  

• omnifunc completion seems to work via i_CTRL-X_CTRL-O
• List all symbols in buffer gO works

Problems

The server logs an error when I try to use gq to format a selection:

ERROR: [Thread 3] No rule matches lsp_formatter:copy_current_alignment(_41008{column:33,leading_spaces:[0],state:[defn_head(18,true),toplevel]},_41004)
ERROR: [Thread 3] In:
ERROR: [Thread 3] [1,063] lsp_formatter:copy_current_alignment(_41100{column:33,leading_spaces:[0],state:[...|...]},_41096)
ERROR: [Thread 3] [1,062] lsp_formatter:correct_indentation(_41100{column:32,leading_spaces:[0],state:[...|...]},[term_begin(;,compound,false),...|...],[term_begin(;,compound,false)|_41218]) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:124
ERROR: [Thread 3]  [198] call_dcg('<garbage_collected>','<garbage_collected>','<garbage_collected>') at c:/program files/swipl/boot/dcg.pl:369
ERROR: [Thread 3]  [194] lsp_formatter:file_format_edits('C:/Users/USER/prolog-lsp-bridge/test.pl',_41298) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_formatter.pl:21
ERROR: [Thread 3]  [193] lsp_server:handle_msg('<garbage_collected>',_41342{id:84,jsonrpc:"2.0",method:"textDocument/rangeFormatting",params:_41362{options: ...,range: ...,textDocument: ...}},_41378{id:84,result:_41384}) at c:/users/USER/appdata/local/swi-prolog/pack/lsp_server/prolog/lsp_server.pl:269
ERROR: [Thread 3]  [192] '<meta-call>'('<garbage_collected>') <foreign>
ERROR: [Thread 3]  [191] catch(lsp_server:(...,...),_41452,lsp_server:(...,...)) at c:/program files/swipl/boot/init.pl:565
ERROR: [Thread 3]  [190] catch_with_backtrace('<garbage_collected>','<garbage_collected>','<garbage_collected>') at c:/program files/swipl/boot/init.pl:645
ERROR: [Thread 3]
ERROR: [Thread 3] Note: some frames are missing due to last-call optimization.
ERROR: [Thread 3] Re-run your program in debug mode (:- debug.) to get more detail.

Attempting grn symbol renaming triggers a new error in neovim (the server doesn't log anything):

Error executing callback:                                                                                   
...gram Files\Neovim\share\nvim\runtime/lua/vim/lsp/rpc.lua:452: assertion failed!
stack traceback:                                                                                                    
[C]: in function 'assert'                                                                                   
...gram Files\Neovim\share\nvim\runtime/lua/vim/lsp/rpc.lua:452: in function 'handle_body'                  
...gram Files\Neovim\share\nvim\runtime/lua/vim/lsp/rpc.lua:600: in function 'handle_body'                  
...gram Files\Neovim\share\nvim\runtime/lua/vim/lsp/rpc.lua:258: in function <...gram Files\Neovim\share\nvim\runtime/lua/vim/lsp/rpc.lua:242>

rpc.lua:452 is the assert line here:

    -- Do not surface RequestCancelled to users, it is RPC-internal.
    if decoded.error then
      assert(type(decoded.error) == 'table')
      if decoded.error.code == protocol.ErrorCodes.RequestCancelled then
        log.debug('Received cancellation ack', decoded)
        -- Clear any callback since this is cancelled now.
        -- This is safe to do assuming that these conditions hold:
        -- - The server will not send a result callback after this cancellation.
        -- - If the server sent this cancellation ACK after sending the result, the user of this RPC
        -- client will ignore the result themselves.
        if result_id then
          self.message_callbacks[result_id] = nil
        end
        return
      end
    end

(The full file is here though line numbers are different than on my installation)

[jamesnvc]

I pushed & deployed a new patch version that should address the error when formatting the selection.

Not sure about the other error with renaming, that's odd. That seems more like something the LSP server is responding with that's the wrong format...not vim-specific at least, so maybe I can track that down myself.