EPERM: operation not permitted, open '...\tmp\build.lock'

coder404 · February 8, 2021, 5:35am

Hello. I’m doing internship at a company and I can compile and run their projects on MacOS. After I switched to Window10, I could successfully build the project, but if I try to modify code and save it, then it shows errors like EPERM: operation not permitted, open ‘…\tmp\build.lock’.

Btw I tried running cmd as administrator. Do anyone have insights on this error? Thanks

rwjblue · February 8, 2021, 12:53pm

A quick search over on GitHub suggests that this build.lock is being written by ember-cli-rails-addon (note: next time including the full stack trace would make finding that info out a bit easier):

github.com

rondale-sc/ember-cli-rails-addon/blob/3faaa5e9e1d88df07cdee62273f26d8d6aa978df/index.js#L38


      app.legacyFilesToAppend.splice(index, 1);
    });
  }
},
preBuild: function(result) {
  var lockFile = this.lockFilePath();
  var errorFile = this.errorFilePath();
  if(!fs.existsSync(lockFile)) {
    fs.openSync(lockFile, 'w');
  }
  if(fs.existsSync(errorFile)) {
    fs.unlinkSync(errorFile);
  }
},
outputReady: function(result){
  var lockFile = this.lockFilePath();

There could be a few different things going on (as far as I can tell at least):

the tmp directory doesn’t exist (and that addon doesn’t try to create it) so attempting to open a file within tmp fails: try making a tmp folder
either tmp or this specific file is marked as hidden in windows (and node has a hard time reading hidden files based on a very quick search)

Hope that helps!