Size

pkgr is a case study in the Floppy Rule. 233 KB on Windows, 117 KB for the published Linux build.

What made the difference

Variant	Size (bytes)
serde_json + dialoguer, default release profile	437,248
serde_json + dialoguer, size profile	318,976
hand-rolled JSON and picker, size profile	251,904
+ ASCII-only case folding	233,984
+ path::absolute instead of canonicalize	233,472

• Hand-rolled JSON scanner: pkgr only needs one object of tasks and one optional string, so there is no document tree and no order-preserving map.
• Hand-rolled picker: talks to each terminal directly, with a small Console trait between the loop and the OS.
• Release profile: opt-level = "z", fat LTO, one codegen unit, panic = "abort", stripped.

Why the Linux build is bigger by default

61% of a normal Linux build is a DWARF parser, a zlib decompressor and a demangler that std links so a panic can print a symbolised backtrace. The published Linux binary is built on a pinned nightly with build-std and panic = immediate-abort, which removes it:

Build	Size
glibc, dynamic	367,048
musl, static	459,320
musl + build-std	418,480
musl + build-std + immediate-abort	116,840

The cost is that a crash is a bare SIGABRT with no message. ./build.sh still produces the stable build, which reports panics normally.

Deliberately not done

Replacing std::process::Command with raw CreateProcessW would save tens of KB, but npm, pnpm and yarn are .cmd shims and Command carries the argument escaping that prevents a script name from running arbitrary commands. Re-implementing that correctly costs what it saves.

The full write-up, with every measurement, is in the README.