The steps to create this build from a stable tagged version are

• Perform a shallow clone of the desired version with

git clone --depth=1 --branch r<n> --single-branch https://github.com/mrdoob/three.js.git

• Add the following lines to src/Three.js just after all other exports

export { OrbitControls } from '../examples/jsm/controls/OrbitControls.js';
export { Line2 } from '../examples/jsm/lines/Line2.js';
export { LineGeometry } from '../examples/jsm/lines/LineGeometry.js';
export { LineMaterial } from '../examples/jsm/lines/LineMaterial.js';
export { LineSegments2 } from '../examples/jsm/lines/LineSegments2.js';
export { LineSegmentsGeometry } from '../examples/jsm/lines/LineSegmentsGeometry.js';

• Move into the library directory with cd three.js

• Configure the library with npm install

• Build the library with npm run build

The minified file will be located in the build directory and has been copied to the same directory here. The final step before releasing is to update the version file with the new number.

As noted in this issue, Three.js releases can be modified for up to a week after the initial release. This build process should wait for this period of time to ensure future consistency of building.