Problem with generating archives from branches/tags since 6.8

Since upgrade to 6.8 I can no longer download archives from the repo. The files in /home/hit/gitlab/tmp/repositories/myrepo.git/ grow to a specific size (different for each project but the same each time) and then stop. The generated tar.gz archives are not valid and cannot be used: gzip: stdin: unexpected end of file

It seems the worker that generates the archive hangs as in the error log there is E, [2014-04-23T10:45:35.285671 #116957] ERROR -- : worker=1 PID:116973 timeout (31s > 30s), killing

It does not help raising the timeout of unicorn to something higher (e. g. 120) - the archive file will always stop at the same size as before and the timeout occurs long after this size has been reached.

It happens on multiple installations of gitlab I use since update to 6.8 from 6.7 (it worked fine before), so it seems not to be related to the servers.

It happens with zip archives, too. Just tested this. Repository size doesn't seem to matter. Just had a repo failing to generate tar.gz from master that has only a few php files in it - no binary.

Servers all use the same OS, debian wheezy.

System information
System:         Debian 7.4
Current User:   git
Using RVM:      no
Ruby Version:   1.9.3p194
Gem Version:    1.8.23                                                                                                                                    
Bundler Version:1.3.5                                                                                                                                     
Rake Version:   10.1.1                                                                                                                                    
Sidekiq Version:2.17.0                                                                                                                                    
                                                                                                                                                          
GitLab information                                                                                                                                        
Version:        6.8.0                                                                                                                                     
Revision:       a0c3643                                                                                                                                   
Directory:      /home/git/gitlab                                                                                                                          
DB Adapter:     mysql2                                                                                                                                    
URL:            http://mydomain.net
HTTP Clone URL: http://mydomain.net/some-project.git
SSH Clone URL:  git@mydomain.net:some-project.git
Using LDAP:     no
Using Omniauth: no

GitLab Shell
Version:        1.9.3
Repositories:   /home/git/repositories/
Hooks:          /home/git/gitlab-shell/hooks/
Git:            /usr/bin/git

Checking Environment ...

Git configured for git user? ... yes

Checking Environment ... Finished

Checking GitLab Shell ...

GitLab Shell version >= 1.9.1 ? ... OK (1.9.3)
Repo base directory exists? ... yes
Repo base directory is a symlink? ... no
Repo base owned by git:git? ... yes
Repo base access is drwxrws---? ... yes
Satellites access is drwxr-x---? ... yes
update hook up-to-date? ... yes
update hooks in repos are links: ... 
-> all repos say "ok" here
Running /home/git/gitlab-shell/bin/check
Check GitLab API access: OK
Check directories and files: 
        /home/git/repositories: OK
        /home/git/.ssh/authorized_keys: OK
Test redis-cli executable: redis-cli 2.4.14
Send ping to redis server: PONG
gitlab-shell self-check successful

Checking GitLab Shell ... Finished

Checking Sidekiq ...

Running? ... yes
Number of Sidekiq processes ... 1

Checking Sidekiq ... Finished

Checking LDAP ...

LDAP is disabled in config/gitlab.yml

Checking LDAP ... Finished

Checking GitLab ...

Database config exists? ... yes
Database is SQLite ... no
All migrations up? ... yes
Database contains orphaned UsersGroups? ... no
GitLab config exists? ... yes
GitLab config outdated? ... no
Log directory writable? ... yes
Tmp directory writable? ... yes
Init script exists? ... yes
Init script up-to-date? ... yes
projects have namespace: ... 
 -> all repositories say "yes" here
Projects have satellites? ... 
 -> all repositories say "yes" here
Redis version >= 2.0.0? ... yes
Your git bin path is "/usr/bin/git"
Git version >= 1.7.10 ? ... yes (1.7.10)

Checking GitLab ... Finished