Can't install project when yarn cache is present and no global git user is configured

Do you want to request a feature or report a bug? bug

What is the current behavior? crash during instlalation

If the current behavior is a bug, please provide the steps to reproduce.

ker@dus:~/my-project λ yarn install
yarn install v1.3.2
info No lockfile found.
[1/5] Validating package.json...
[2/5] Resolving packages...
error Command failed.
Exit code: 128
Command: git
Arguments: pull
Directory: /home/keradus/.cache/yarn/v1/.tmp/5fe5dc997bcb53d9983a4dae633fdd3f
Output:
From git://github.com/adobe-fonts/source-sans-pro
   77ad88165..d975556bf  master     -> origin/master
 * [new branch]          PaulFix    -> origin/PaulFix
 * [new branch]          bulg-cyr   -> origin/bulg-cyr

*** Please tell me who you are.

Run

  git config --global user.email "you@example.com"
  git config --global user.name "Your Name"

to set your account's default identity.
Omit --global to set the identity only in this repository.

fatal: unable to auto-detect email address (got 'keradus@XXX.(none)')
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

What is the expected behavior? not crashing, eg using dummy git user

Please mention your node.js, yarn and operating system version. node 8.9.4, ubuntu