Import from Bitbucket to Gitlab fails

I'm using gitlab on my Raspberry Pi 2 B using Let's encrypt certificates. I configured the bitbucket oauth as described here (http://stratus3d.com/blog/2015/09/06/migrating-from-bitbucket-to-local-gitlab-server/).

Problem: The first import by an existing repo from bitbucket to gitlab succeeds, but when I try importing another repos, it fails. Another strange thing is, that the "Import all projects" Button is always loading regardless I am importing or not. New: The first import process after gitlab-ctl restart succeeds.

Question: Is there any way to find details about why the import failed in detail? The production.log does not contain something helpful. Why does one import process succeed after restarting gitlab?

Things I tried:

3x redoing the methods exactly described in the tutorial above (incl. new SSH Keys and new API Keys)
changing timeouts in gitlab.rb
CPU and RAM usage is normal and do not exceed the limits
restarting gitlab, restarting server etc. (After restart one import process succeeds)

My Configuration:

Raspberry Pi
    A 900MHz quad-core ARM Cortex-A7 CPU
    1GB RAM
    Raspbian on 64GB USB 3.0 Stick

    Gitlab

        GitLab 8.7.3

        GitLab Shell 2.7.2

        GitLab API v3

        Git 2.7.4

        Ruby 2.1.8p440

        Rails 4.2.6

        PostgreSQL 9.2.15
    Let's encrypt SSL Certificates

Could someone help me, please?

cc @DouweM @balameb

I'll be happy to assist on this as soon as I have some time.

I did test this a few times locally on EE/CE using GDK and it worked fine. May have to try with the omnibus packages...

thank you for your help :)

mentioned in issue #17401 (closed)

mentioned in merge request !4106 (merged)

Reassigned to @jameslopez

Milestone changed to 8.7

Added ~12980 import labels

Status changed to closed by merge request !4106 (merged)

mentioned in commit f4d2a2d9

mentioned in commit 32ef666d

I updated gitlab to 7.5 and this issue still exists. Additionally I noticed that the target folder for import is wrong. The first attempt importing a project to gitlab after restart is still successful. I appended a Screenshot which shows the source folder "julianpoemp/test2" (bitbucket) and the target folder "julianpoemp/test2" (gitlab), but the target folder should be named as "julian/test2".

@J.Poemp The fix didn't make it to 8.7.5 and will go into 8.7.6 - See https://gitlab.com/gitlab-org/gitlab-ce/issues/17490. The target folder problem does not seem related to this, it would be great if you can create a separate issue with the details for that... Thanks!

Mentioned in commit pfjason/gitlab-ce@32ef666d

Mentioned in commit pfjason/gitlab-ce@f4d2a2d9