node 26 bottle is built without Temporal support

[Leask]

brew config AND brew doctor output

Your system is ready to brew.
HOMEBREW_VERSION: 5.1.10-33-g6839384
ORIGIN: https://github.com/Homebrew/brew
HEAD: 68393841da13d154749e0d332e20a3b69250a83e
Last commit: 2 hours ago
Branch: main
Core tap HEAD: 7a8dfb265ff976e34a5879fd5993d6de4495fa51
Core tap last commit: 19 minutes ago
Core tap JSON: 08 May 15:44 UTC
Core cask tap HEAD: 8b52a10df8ade147b6cf6632ce9af87d17cc106e
Core cask tap last commit: 40 minutes ago
Core cask tap JSON: 08 May 15:44 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: /var/run/com.apple.launchd.8YEix1pkaJ/org.xquartz:0
HOMEBREW_DOWNLOAD_CONCURRENCY: 48
HOMEBREW_EDITOR: /usr/bin/vim
HOMEBREW_FORBID_PACKAGES_FROM_PATHS: set
HOMEBREW_MAKE_JOBS: 24
HOMEBREW_NO_COLOR: set
HOMEBREW_NO_ENV_HINTS: set
HOMEBREW_SORBET_RUNTIME: set
Homebrew Ruby: 4.0.3 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/4.0.3/bin/ruby
CPU: 24-core 64-bit arm_blizzard_avalanche
Clang: 21.0.0 build 2100
Git: 2.54.0 => /opt/homebrew/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 26.5-arm64
CLT: N/A
Xcode: 26.4.1
Metal Toolchain: N/A
Rosetta 2: false

Verification

• My brew doctor output says Your system is ready to brew. and am still able to reproduce my issue.
• I ran brew update and am still able to reproduce my issue.
• I have resolved all warnings from brew doctor and that did not fix my problem.
• I searched for recent similar issues at https://github.com/Homebrew/homebrew-core/issues?q=is%3Aissue and found no duplicates.
• My issue is not about a failure to build a formula from source.

What were you trying to do (and why)?

Use the native Temporal API in Node.js 26, specifically Temporal.Now.zonedDateTimeISO().toString().

Node.js 26 enables Temporal by default upstream, so I expected the Homebrew node 26 bottle to expose globalThis.Temporal as well.

What happened (include all command output)?

Homebrew's node 26 bottle appears to be built without V8 Temporal support:

$ brew info node | sed -n '1,20p'
==> node: stable 26.0.0 (bottled), HEAD
Open-source, cross-platform JavaScript runtime environment
https://nodejs.org/
Installed (on request)
/opt/homebrew/Cellar/node/26.0.0 (1,889 files, 82.4MB) *
  Poured from bottle using the formulae.brew.sh API on 2026-05-08 at 10:50:32
From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/n/node.rb
License: MIT
==> Dependencies
Required (17): ada-url, brotli, c-ares, hdrhistogram_c, icu4c@78, libnghttp2, libnghttp3, libngtcp2, libuv, llhttp, merve, nbytes, openssl@3, simdjson, sqlite, uvwasi, zstd
Recursive Runtime (23): all installed ✔

$ node -p "JSON.stringify({version: process.version, execPath: process.execPath, v8: process.versions.v8, temporalGlobal: Object.hasOwn(globalThis, 'Temporal'), temporalNow: typeof globalThis.Temporal?.Now?.zonedDateTimeISO, temporalConfig: process.config.variables.v8_enable_temporal_support}, null, 2)"
{
  "version": "v26.0.0",
  "execPath": "/opt/homebrew/Cellar/node/26.0.0/bin/node",
  "v8": "14.6.202.33-node.19",
  "temporalGlobal": false,
  "temporalNow": "undefined",
  "temporalConfig": 0
}

For comparison, the official upstream Node.js v26.0.0 darwin-arm64 binary exposes Temporal and has v8_enable_temporal_support = 1:

$ ./node-v26.0.0-darwin-arm64/bin/node -p "JSON.stringify({version: process.version, execPath: process.execPath, temporalGlobal: Object.hasOwn(globalThis, 'Temporal'), temporalNow: typeof globalThis.Temporal?.Now?.zonedDateTimeISO, temporalConfig: process.config.variables.v8_enable_temporal_support, sample: globalThis.Temporal?.Now?.zonedDateTimeISO?.().toString()}, null, 2)"
{
  "version": "v26.0.0",
  "execPath": "/private/var/folders/d6/j_bw829j50dc21f_98rtdslh0000gn/T/tmp.uwJLyoHm6d/node-v26.0.0-darwin-arm64/bin/node",
  "temporalGlobal": true,
  "temporalNow": "function",
  "temporalConfig": 1,
  "sample": "2026-05-08T11:53:36.18027002-04:00[America/Toronto]"
}

The formula also seems to know that temporal_capi is only relevant when building with --v8-enable-temporal-support, but I do not see --v8-enable-temporal-support being added to the configure args:

$ brew cat node | rg -n "v8-enable-temporal|temporal_capi|args =|configure" -C 3
99-
100-    # Never install the bundled "npm", always prefer our
101-    # installation from tarball for better packaging control.
102:    args = %W[
103-      --prefix=#{prefix}
104-      --without-npm
105-      --with-intl=system-icu
--
142-    # TODO: Try to devendor these libraries.
143-    # - `--shared-gtest` is only used for building the test suite, which we don't run here.
144-    # - `--shared-simdutf` seems to result in build failures.
145:    # - `--shared-temporal_capi` is only used when building with `--v8-enable-temporal-support`
146-    # - `--shared-lief` is not available as dependency in Homebrew.
147-    ignored_shared_flags = %w[
148-      gtest
149-      simdutf
150:      temporal_capi
151-      lief
152-    ].map { |library| "--shared-#{library}" }
--
173-    # FIXME: re-enable me, currently crashes sequoia runner after 6 hours
174-    # args << "--enable-lto" if OS.mac? && DevelopmentTools.clang_build_version > 1699 && build.bottle?
175-
176:    system "./configure", *args
177-    system "make", "install"

What did you expect to happen?

Homebrew's node 26 bottle should match upstream Node.js 26 behavior:

Object.hasOwn(globalThis, 'Temporal') === true
process.config.variables.v8_enable_temporal_support === 1
typeof Temporal.Now.zonedDateTimeISO === 'function'

If Homebrew's configure environment disables V8's default Temporal support, the formula may need to pass --v8-enable-temporal-support explicitly, and possibly handle the temporal_capi dependency accordingly.

Step-by-step reproduction instructions (by running brew commands)

brew update
brew reinstall node
node -p "JSON.stringify({version: process.version, execPath: process.execPath, v8: process.versions.v8, temporalGlobal: Object.hasOwn(globalThis, 'Temporal'), temporalNow: typeof globalThis.Temporal?.Now?.zonedDateTimeISO, temporalConfig: process.config.variables.v8_enable_temporal_support}, null, 2)"

[Leask]

Opened PR #281626 to enable V8 Temporal support in the Node formula and add a formula test assertion for Temporal.Now.zonedDateTimeISO.

[Leask]

Update: I opened an upstream V8 CL for the underlying Temporal/system-ICU problem:

https://chromium-review.googlesource.com/c/v8/v8/+/7831715

The V8-side design is to stop loading Temporal's zoneinfo64.res through ICU private APIs in i18n builds. Instead, V8 would always use its existing generated zoneinfo64_static_data path whenever Temporal is enabled. That makes the i18n and non-i18n Temporal timezone data path consistent and removes the dependency on ICU private headers such as udatamem.h.

Expected effect for this Homebrew issue:

• Node built with system/shared ICU should no longer lose Temporal support because of V8's private ICU data-loading path;
• the no-ICU/static-data path should continue to work because the generated zoneinfo64 blob is always linked when Temporal is enabled;
• Homebrew should eventually be able to keep the normal system/shared ICU packaging model while still exposing globalThis.Temporal in Node 26+.

For now, this depends on upstream V8 review/landing and then Node consuming the fix through a V8 roll or backport. The replacement Homebrew PR #281707 remains the practical packaging workaround if maintainers want Temporal enabled before that upstream path lands, but the longer-term fix should be upstream V8/Node rather than a permanent Homebrew-specific workaround.

[p-linnane]

I think we've come to the consensus that this needs to be handled upstream before we will support it. Closing this out.

[cho-m]

Noting that we can enable support after upstream PR is merged:

• deps: V8: fix Temporal with system-icu nodejs/node#65992

PR to try out backporting commits after we merge 26.10.0:

• node 26.10.0 #313118

[srl295]

Landed upstream