Bug: running 2 (maybe more) yarn commands on different projects the same time fails

[neophob]

I installed yarn the first time, then i ran yarnon project A, seconds later I ran yarn on project B.

Both installation failed, project A output:

yarn install v0.15.1
info No lockfile found.
[1/4] 🔍  Resolving packages...
[2/4] 🚚  Fetching packages...
error Couldn't find a package.json (or bower.json) file in /Users/USERNAME/.yarn-cache/npm-yargs-3.10.0
    at /usr/local/lib/node_modules/yarnpkg/lib-legacy/config.js:363:13
    at next (native)
    at step (/usr/local/lib/node_modules/yarnpkg/node_modules/babel-runtime/helpers/asyncToGenerator.js:17:30)
    at /usr/local/lib/node_modules/yarnpkg/node_modules/babel-runtime/helpers/asyncToGenerator.js:28:20
    at run (/usr/local/lib/node_modules/yarnpkg/node_modules/core-js/library/modules/es6.promise.js:87:22)
    at /usr/local/lib/node_modules/yarnpkg/node_modules/core-js/library/modules/es6.promise.js:100:28
    at flush (/usr/local/lib/node_modules/yarnpkg/node_modules/core-js/library/modules/_microtask.js:18:9)
    at nextTickCallbackWith0Args (node.js:415:9)
    at process._tickCallback (node.js:344:13)

project B output:

yarn install v0.15.1
info No lockfile found.
[1/4] 🔍  Resolving packages...
[2/4] 🚚  Fetching packages...
error Couldn't find a package.json (or bower.json) file in /Users/USERNAME/.yarn-cache/npm-yargs-4.8.1
    at /usr/local/lib/node_modules/yarnpkg/lib-legacy/config.js:363:13
    at next (native)
    at step (/usr/local/lib/node_modules/yarnpkg/node_modules/babel-runtime/helpers/asyncToGenerator.js:17:30)
    at /usr/local/lib/node_modules/yarnpkg/node_modules/babel-runtime/helpers/asyncToGenerator.js:28:20
    at run (/usr/local/lib/node_modules/yarnpkg/node_modules/core-js/library/modules/es6.promise.js:87:22)
    at /usr/local/lib/node_modules/yarnpkg/node_modules/core-js/library/modules/es6.promise.js:100:28
    at flush (/usr/local/lib/node_modules/yarnpkg/node_modules/core-js/library/modules/_microtask.js:18:9)
    at nextTickCallbackWith0Args (node.js:415:9)
    at process._tickCallback (node.js:344:13)

When I run those commands sequentially it works as expected.

versions:

• node 4.5
• yarn 0.15.1
• osx 10.11.6

[moneytree-doug]

Confirmed.

$ node -v
v5.7.1
$ yarn -v

Edit: Now I am just stuck in this state.

[timche]

This bug has to be resolved in order to make Lerna compatible with Yarn, because Lerna spawns multiple concurrent processes of npm install.

[moneytree-doug]

@timche Thanks for the update. I'll check it out again tonight.

[steelbrain]

@moneytree-doug I think you might have misunderstood what he said. He didn't say that it has been resolved but rather has to be resolved :)

[moneytree-doug]

@steelbrain Haha, whoops!

[darabos]

I ended up with a partially written file in ~/.yarn-cache due to such a collision in parallel invocation from Jenkins tests. (gulp-jshint/src/reporters/fail.js was truncated to 512 bytes.) yarn would then successfully run, just copying the broken file from .yarn-cache to the destination directory. 😩

[diegov]

Adding my case here since we're in a similar situation, with multiple yarn instances running concurrently. In my case the error I got was
Trace: Error: https://registry.yarnpkg.com/@types/node/-/node-6.0.46.tgz: EEXIST: file already exists, mkdir '/home/administrator/.yarn-cache/npm-@types/node-6.0.46' at Error (native)

[STRML]

Seeing this as well if Jenkins happens to run multiple builds at the same time.

The error is very short:

Trace:
  Error: http://x.x.x.x:xxxx/autoprefixer/-/autoprefixer-6.5.3.tgz: ENOENT: no such file or directory, utime '/var/lib/jenkins/.yarn-cache/npm-autoprefixer-6.5.3/package.json'
      at Error (native)