engines.node rejects Node.js Alpha versions (27.0.0-alpha.x.y.z) #10169

Starting with Node.js 27, the release line is published as Alpha versions between the branch-off in October and the semver-major release in April. The first one, v27.0.0-alpha.0.0.0, is scheduled for tomorrow (2026-10-28). See nodejs/Release#1187 and nodejs/node#67062.

npm 12.1.0 declares engines.node as ^22.22.2 || ^24.15.0 || >=26.0.0. A prerelease version only satisfies a range when a comparator carries a prerelease on the same major.minor.patch, so 27.0.0-alpha.0.0.0 does not match >=26.0.0 and every npm invocation on the Alpha prints:

npm v12.1.0 does not support Node.js v27.0.0-alpha.0.0.0. This version of npm supports the following node versions: `^22.22.2 || ^24.15.0 || >=26.0.0`. You can find the latest version at https://nodejs.org/.

This also fails test/parallel/test-release-npm.js in the Node.js release build, which checks that npm starts without warnings: https://github.com/nodejs/node/actions/runs/40526983886/job/122270723233

Alpha versions will be released on the 27 line until April 2027, and every future major will go through the same phase, so a general approach might be preferred (for example >=N.0.0-alpha for the upcoming major whenever the >= comparator is bumped).