build fails in docker but not elsewhere.

[okolloen]

• polymer build info: [cli.command.build] Clearing build/ directory... info: [cli.build.build] (es6-unbundled) Building... error: [cli.main] Uncaught exception: RangeError [ERR_OUT_OF_RANGE]: The value of "mode" is out of range. Received 33206 error: [cli.main] RangeError [ERR_OUT_OF_RANGE]: The value of "mode" is out of range. Received 33206 at Object.fs.fchmod (fs.js:1056:11) at Object.fchmod (/usr/local/lib/node_modules/polymer-cli/node_modules/graceful-fs/polyfills.js:237:17) at mode (/usr/local/lib/node_modules/polymer-cli/node_modules/vinyl-fs/lib/fileOperations.js:132:10) at onStat (/usr/local/lib/node_modules/polymer-cli/node_modules/vinyl-fs/lib/fileOperations.js:125:14) at /usr/local/lib/node_modules/polymer-cli/node_modules/graceful-fs/polyfills.js:287:18 at FSReqWrap.oncomplete (fs.js:183:5)

A clue might be : https://github.com/isaacs/node-graceful-fs/issues/129