perf(build): upgrade rust-i18n v3 -> v4 to fix codegen blowup

Release builds consumed 5+ GB and never completed on a 4-core / 7.6 GB
VM, thrashing the machine badly enough to lose SSH access.

Root cause was a codegen bug in rust-i18n v3, not machine size. Its
macro emitted one HashMap::from([...]) and one add_translations() call
per translation string, all in a single function body -- 8,652 of each
for our 21 locales / ~9,000 keys. LLVM scales superlinearly on function
size, so optimising that one initialiser took ~4.5 GB.

Verified via cargo expand (lib target):

                          v3.1.5    v4.2.1
  HashMap::from            8,652         0
  add_translations         8,652        21   (one per locale)
  expanded lines          93,026    73,444

Fixed upstream in v4.0.0.

Clean release builds, same machine:

  v3, opt-level=3, thin LTO      5.2 GB   stalled >18m, never finished
  v3, opt-level=1, no LTO        1.8 GB   15m30s   (previous workaround)
  v4, opt-level=3, thin LTO      2.08 GB  3m25s
  v4, stock cargo defaults       1.92 GB  2m17s

Also:
- Remove the opt-level=1 / lto=false workaround; cargo's release
  defaults are correct now. No shipped code is de-optimised.
- Keep only genuine small-machine hygiene in .cargo/config.toml:
  jobs=3 (keeps the box interactive), lld linker, and trimmed debug
  info on dev/test profiles.
- Document the diagnosis, the cargo expand / llvm-lines workflow that
  found it, and the systemd-based safety nets in docs/BUILDING.md.
- Note in main.rs why i18n! must appear in both crate roots (t! expands
  to crate::_rust_i18n_t, and main.rs re-declares the module tree
  rather than depending on the lib target).

Test suite passes; release binary verified working.
This commit is contained in:
2026-08-07 00:17:21 +00:00
parent d539c8abe7
commit a728c758a7
5 changed files with 312 additions and 15 deletions
Generated
+83 -14
View File
@@ -2,6 +2,19 @@
# It is not intended for manual editing.
version = 4
[[package]]
name = "ahash"
version = "0.8.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "5a15f179cd60c4584b8a8c596927aadc462e27f2ca70c04e0071964a73ba7a75"
dependencies = [
"cfg-if",
"getrandom 0.3.4",
"once_cell",
"version_check",
"zerocopy",
]
[[package]]
name = "aho-corasick"
version = "1.1.4"
@@ -32,6 +45,17 @@ version = "0.1.6"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "4b46cbb362ab8752921c97e041f5e366ee6297bd428a31275b9fcf1e380f7299"
[[package]]
name = "annotate-snippets"
version = "0.12.16"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f211a51805bc641f3ad5b7664c77d2547af685cc33b4cd8d31964027a46f13f1"
dependencies = [
"anstyle",
"memchr",
"unicode-width",
]
[[package]]
name = "anstream"
version = "0.6.21"
@@ -97,6 +121,12 @@ dependencies = [
"rustversion",
]
[[package]]
name = "arraydeque"
version = "0.5.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "7d902e3d592a523def97af8f317b08ce16b7ab854c1985a0c671e6f15cebc236"
[[package]]
name = "atomic"
version = "0.6.1"
@@ -633,6 +663,15 @@ dependencies = [
"cfg-if",
]
[[package]]
name = "encoding_rs_io"
version = "0.1.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "fba3fe847045ecff794b9c138293a80db914678c453ad63fbf0c6a9eb6e00b22"
dependencies = [
"encoding_rs",
]
[[package]]
name = "equivalent"
version = "1.0.2"
@@ -817,9 +856,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
dependencies = [
"cfg-if",
"js-sys",
"libc",
"r-efi",
"wasip2",
"wasm-bindgen",
]
[[package]]
@@ -852,6 +893,16 @@ dependencies = [
"walkdir",
]
[[package]]
name = "granit-parser"
version = "0.0.7"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d03f81ad4732830d85cfd417a9f62cde6dadda4354d37d078a6084a19560aa2d"
dependencies = [
"arraydeque",
"smallvec",
]
[[package]]
name = "h2"
version = "0.4.13"
@@ -1491,6 +1542,12 @@ dependencies = [
"memoffset",
]
[[package]]
name = "nohash-hasher"
version = "0.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "2bf50223579dc7cdcfb3bfcacf7069ff68243f8c363f62ffa99cf000a6b9c451"
[[package]]
name = "nom"
version = "7.1.3"
@@ -2123,12 +2180,11 @@ dependencies = [
[[package]]
name = "rust-i18n"
version = "3.1.5"
version = "4.2.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "fda2551fdfaf6cc5ee283adc15e157047b92ae6535cf80f6d4962d05717dc332"
checksum = "f10cee36dd3b1f7929ea12b759de9eea9eff83bfccbc71f387ef4d41a57c64a4"
dependencies = [
"globwalk",
"once_cell",
"regex",
"rust-i18n-macro",
"rust-i18n-support",
@@ -2137,39 +2193,33 @@ dependencies = [
[[package]]
name = "rust-i18n-macro"
version = "3.1.5"
version = "4.2.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "22baf7d7f56656d23ebe24f6bb57a5d40d2bce2a5f1c503e692b5b2fa450f965"
checksum = "f0bb1ed4e04fe26c2a2652cad1c6595efaf7196f4445c0d6e13c67154347fb7e"
dependencies = [
"glob",
"once_cell",
"proc-macro2",
"quote",
"rust-i18n-support",
"serde",
"serde_json",
"serde_yaml",
"syn 2.0.114",
]
[[package]]
name = "rust-i18n-support"
version = "3.1.5"
version = "4.2.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "940ed4f52bba4c0152056d771e563b7133ad9607d4384af016a134b58d758f19"
checksum = "ba1c083408a2733180ae0acf2897612f8ceec7b0c0dcd065a0a87103bfb3b1d9"
dependencies = [
"arc-swap",
"base62",
"globwalk",
"itertools 0.11.0",
"lazy_static",
"normpath",
"once_cell",
"proc-macro2",
"regex",
"serde",
"serde-saphyr",
"serde_json",
"serde_yaml",
"siphasher",
"toml",
"triomphe",
@@ -2318,6 +2368,25 @@ dependencies = [
"serde_derive",
]
[[package]]
name = "serde-saphyr"
version = "0.0.29"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "7bd22781911de0ca6debda95f073c8f18bec65d1a94f1fa9573f3102e514cea4"
dependencies = [
"ahash",
"annotate-snippets",
"base64",
"encoding_rs_io",
"getrandom 0.3.4",
"granit-parser",
"nohash-hasher",
"num-traits",
"serde_core",
"smallvec",
"zmij",
]
[[package]]
name = "serde_core"
version = "1.0.228"