buildInputs = [ clang-tools clang ];

vim-lsp.log

Wed 25 Dec 2019 01:56:05 AM PST:["s:on_text_document_did_open()",1,"c","/home/spearman/c/try/tryconst","file:///home/spearman/c/try/tryconst/main.c"]
Wed 25 Dec 2019 01:56:05 AM PST:[{"response":{"data":{"__data__":"vim-lsp","lsp_id":1,"server_name":"clangd"},"message":"started lsp server successfully"}}]
Wed 25 Dec 2019 01:56:05 AM PST:["--->",1,"clangd",{"method":"initialize","params":{"rootUri":"file:///home/spearman/c/try/tryconst","capabilities":{"workspace":{"configuration":true,"applyEdit":true},"textDocument":{"foldingRange":{"lineFoldingOnly":true},"documentSymbol":{"symbolKind":{"valueSet":[10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,1,2,3,4,5,6,7,8,9]}},"definition":{"linkSupport":true},"completion":{"completionItem":{"snippetSupport":false,"documentationFormat":["plaintext"]},"completionItemKind":{"valueSet":[10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,1,2,3,4,5,6,7,8,9]}},"implementation":{"linkSupport":true},"declaration":{"linkSupport":true},"typeDefinition":{"linkSupport":true}}},"rootPath":"/home/spearman/c/try/tryconst","processId":9029,"trace":"off"}}]
Wed 25 Dec 2019 01:56:05 AM PST:["<---(stderr)",1,"clangd",["I["]]
Wed 25 Dec 2019 01:56:05 AM PST:["<---",1,"clangd",{"response":{"id":1,"jsonrpc":"2.0","result":{"capabilities":{"documentSymbolProvider":true,"documentHighlightProvider":true,"hoverProvider":true,"workspaceSymbolProvider":true,"documentFormattingProvider":true,"signatureHelpProvider":{"triggerCharacters":["(",","]},"executeCommandProvider":{"commands":["clangd.applyFix"]},"documentOnTypeFormattingProvider":{"moreTriggerCharacter":[],"firstTriggerCharacter":"}"},"definitionProvider":true,"renameProvider":true,"codeActionProvider":true,"completionProvider":{"resolveProvider":false,"triggerCharacters":[".",">",":"]},"documentRangeFormattingProvider":true,"textDocumentSync":2}}},"request":{"id":1,"jsonrpc":"2.0","method":"initialize","params":{"rootUri":"file:///home/spearman/c/try/tryconst","capabilities":{"workspace":{"configuration":true,"applyEdit":true},"textDocument":{"foldingRange":{"lineFoldingOnly":true},"documentSymbol":{"symbolKind":{"valueSet":[10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,1,2,3,4,5,6,7,8,9]}},"definition":{"linkSupport":true},"completion":{"completionItem":{"snippetSupport":false,"documentationFormat":["plaintext"]},"completionItemKind":{"valueSet":[10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,1,2,3,4,5,6,7,8,9]}},"implementation":{"linkSupport":true},"declaration":{"linkSupport":true},"typeDefinition":{"linkSupport":true}}},"rootPath":"/home/spearman/c/try/tryconst","processId":9029,"trace":"off"}}}]
Wed 25 Dec 2019 01:56:05 AM PST:["--->",1,"clangd",{"method":"initialized","params":{}}]
Wed 25 Dec 2019 01:56:05 AM PST:[{"response":{"data":{"__data__":"vim-lsp","server_name":"clangd"},"message":"configuration sent"}}]
Wed 25 Dec 2019 01:56:05 AM PST:["s:update_file_content()",1]
Wed 25 Dec 2019 01:56:05 AM PST:["--->",1,"clangd",{"method":"textDocument/didOpen","params":{"textDocument":{"uri":"file:///home/spearman/c/try/tryconst/main.c","version":1,"languageId":"c","text":"#include <stdio.h>\n\nint main() {\n  puts (\"main...\");\n  int const x = 5;\n  printf (\"%i\\n\", x);\n  puts (\"...main\");\n}\n"}}}]
Wed 25 Dec 2019 01:56:05 AM PST:[{"response":{"data":{"path":"file:///home/spearman/c/try/tryconst/main.c","__data__":"vim-lsp","filetype":"c","server_name":"clangd"},"message":"textDocument/open sent"}}]
Wed 25 Dec 2019 01:56:05 AM PST:[{"response":{"data":{"path":"file:///home/spearman/c/try/tryconst/main.c","__data__":"vim-lsp","server_name":"clangd"},"message":"not dirty"}}]
Wed 25 Dec 2019 01:56:05 AM PST:["<---(stderr)",1,"clangd",["01:56:05.820] <-- initialize(1)","I[01:56:05.820] --> reply(1)","I[01:56:05.827] <-- initialized","E[01:56:05.827] Error -32601: method not found","I[01:56:05.837] <-- textDocument/didOpen","I[01:56:05.837] Failed to find compilation database for /home/spearman/c/try/tryconst/main.c","I[01:56:05.837] Updating file /home/spearman/c/try/tryconst/main.c with command [/home/spearman/c/try/tryconst] clang /home/spearman/c/try/tryconst/main.c -resource-dir=/nix/store/iy3630wvgw1iv1fycafhgzb004r3jbjk-clang-7.1.0/bin/../lib/clang/7.1.0",""]]
Wed 25 Dec 2019 01:56:05 AM PST:["<---",1,"clangd",{"response":{"method":"textDocument/publishDiagnostics","jsonrpc":"2.0","params":{"diagnostics":[],"uri":"file:///home/spearman/c/try/tryconst/main.c"}}}]
Wed 25 Dec 2019 01:56:10 AM PST:["s:on_text_document_did_close()",1]