uutils/coreutils — pull request #254 by ebfe (2014-06-16 19:15:03+00:00)
Title: c_types: handle errors from getgroups()/getgrouplist()

The most likely reason for #236 is that either the getgroups() or getgrouplist() call fails, setting ngroups to -1.
ngroups is then used to size the `groups` Vec via `set_len(ngroups as uint)` which is obviously wrong in that case.