Fix shdeps Lua bootstrap without debug source paths (#27)

Fix shdeps Lua bootstrap loading for embedded Lua hosts that do not
provide
file-backed debug source metadata.

`bootstrap.load()` already knows the selected `lua/shdeps.lua` candidate
path,
so it now loads the chunk with `loadfile()` and passes that path through
chunk
varargs. The public Lua module uses the injected source path for sibling
discovery before falling back to `debug.getinfo`, keeping direct loads
working
as before while avoiding host-specific behavior or global state.

The regression test clears `debug` while loading the real public module
through
bootstrap, covering the no-debug-source-path case.

Testing:

- `checkrun lint lua/shdeps.lua lua/shdeps/bootstrap.lua
tests/shell/lua-bootstrap-test`
- `git diff --check`
- `tests/shell/lua-bootstrap-test` with `lua` backed by `nvim --headless
-l`
- `tests/shell/lua-api-test` with `lua` backed by `nvim --headless -l`
- `tests/shell/install-sh-test`
- `tests/shell/installer-flow-test`
- `tests/shell/release-scripts-test`
- `cargo test --locked`
- `cargo clippy --locked --all-targets -- -D warnings`
- `RUSTDOCFLAGS='-D missing-docs' cargo doc --locked --no-deps`

Author: cgraf78

lua/shdeps.lua

@@ -17,7 +17,13 @@
 -- Runtime hosts that need to discover the installed shdeps module can load
 -- `lua/shdeps/bootstrap.lua` and call `bootstrap.load(options)`.
 
+local injected_source = ...
+
 local function source_path()
+  if type(injected_source) == "string" and injected_source:match("%.lua$") then
+    return (injected_source:gsub("^@", ""):gsub("\\", "/"))
+  end
+
   if type(debug) ~= "table" or type(debug.getinfo) ~= "function" then
     return nil
   end

lua/shdeps/bootstrap.lua

@@ -104,7 +104,19 @@ end
 function M.load(options)
   for _, path in ipairs(candidates(options)) do
     if readable(path) then
-      return dofile(path)
+      -- Some embedders compile configuration chunks without file-backed debug
+      -- metadata. Bootstrap already owns the selected candidate path, so pass
+      -- that path through the loaded chunk's varargs for sibling discovery.
+      local chunk, load_error = loadfile(path)
+      if not chunk then
+        error(load_error, 0)
+      end
+
+      local ok, module = pcall(chunk, path)
+      if ok then
+        return module
+      end
+      error(module, 0)
     end
   end
 

tests/shell/lua-bootstrap-test

@@ -45,6 +45,15 @@ LUA
 )
 _assert_eq "lua bootstrap: explicit module path wins" "explicit" "$result"
 
+result=$(
+  SHDEPS_BOOTSTRAP="$bootstrap" SHDEPS_REAL_LUA="$REPO_ROOT/lua/shdeps.lua" lua <<'LUA'
+local bootstrap = dofile(os.getenv("SHDEPS_BOOTSTRAP"))
+debug = nil
+print(bootstrap.load({ lua = os.getenv("SHDEPS_REAL_LUA") }).API_VERSION)
+LUA
+)
+_assert_eq "lua bootstrap: explicit real module loads without debug source paths" "1" "$result"
+
 root="$fixture/root"
 _write_fake_module "$root" root
 result=$(