The client tsdown presets found a package's own manifest by name: a glob of
every packages/*/*/package.json, parsed until the name matched. tsdown's
native config loader imports each package config without module cache, so
the module-level cache never hit and all 82 configs repeated the glob
(40-125 ms each) synchronously on tsdown's main thread, where it delayed
every other package build. It was 34.5% of the client pass's main thread.
- clientBundle, staticLinked and clientLibrary take the package directory
(import.meta.dirname at every call site) and read <dir>/package.json
once; the package name, loader id and externals come from that manifest.
- A missing, unreadable or nameless manifest throws an actionable error.
- The glob, the name search and the module-level caches are removed.
tsdown client pass 12.78 s -> 8.73 s (median of 3 interleaved runs each,
-31.7%); all 11,566 lib outputs byte-identical; all 82 configs resolve the
same externals and banners.
Refs #5852
imccyu