Unable to clone using HTTPS (empty repository)

I recently upgraded from Debian Wheezy to Jessie, and got Apache 2.4 (from 2.2). After some changes to the conf files, I managed to get Gitlab back (I am using a relative URL + HTTPS), but I cannot clone using HTTPS.

I cannot clone from a remote host:

$ git clone https://domain.com/gitlab/mikael/test.git
Cloning into 'test'...
Username for 'https://domain.com': mikael
Password for 'https://mikael@domain.com':
warning: You appear to have cloned an empty repository.
Checking connectivity... done.

Or from localhost:

# git clone http://localhost:8181/gitlab/mikael/test.git
Cloning into 'test'...
Username for 'http://localhost:8181': mikael
Password for 'http://mikael@localhost:8181':
warning: You appear to have cloned an empty repository.
Checking connectivity... done.

I read lots of topics but can't get it working. What I have done (from the various posts I found):

Updating /etc/apache2/conf-enabled/gitlab.conf:

Alias /gitlab "/home/git/gitlab/public/"
<Directory "/home/git/gitlab/public">

    Options Indexes FollowSymLinks MultiViews
    AllowOverride All
    Options -MultiViews
    Require all granted

    RailsEnv production
    PassengerAppRoot /home/git/gitlab

    RewriteEngine On

    # Forward these requests to gitlab-workhorse
    RewriteCond %{REQUEST_URI} ^/[\w\.-]+/[\w\.-]+/gitlab-lfs/objects.* [OR]
    RewriteCond %{REQUEST_URI} ^/[\w\.-]+/[\w\.-]+/builds/download.* [OR]
    RewriteCond %{REQUEST_URI} ^/[\w\.-]+/[\w\.-]+/repository/archive.* [OR]
    RewriteCond %{REQUEST_URI} ^/api/v3/projects/.*/repository/archive.* [OR]
    RewriteCond %{REQUEST_URI} ^/ci/api/v1/builds/[0-9]+/artifacts.* [OR]
    RewriteCond %{REQUEST_URI} ^/[\w\.-]+/[\w\.-]+/(info/refs|git-upload-pack|git-receive-pack)$
    RewriteRule .* http://127.0.0.1:8181%{REQUEST_URI} [P,QSA,NE]

    # Forward request ending with .git to gitlab-git-http-server
    RewriteCond %{REQUEST_URI} [-\/\w\.]+\.git\/
    RewriteRule .* http://127.0.0.1:8181%{REQUEST_URI} [P,QSA]

    # Forward any other requests to GitLab Rails app (Unicorn)
    RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f [OR]
    RewriteCond %{REQUEST_URI} ^/uploads
    RewriteRule .* http://127.0.0.1:8080%{REQUEST_URI} [P,QSA,NE]
    RequestHeader set X_FORWARDED_PROTO 'https'
    RequestHeader set X-Forwarded-Ssl on
</Directory>

Update /etc/default/gitlab:

gitlab_workhorse_options="-listenUmask 022 -listenNetwork tcp -listenAddr 127.0.0.1:8181 -authBackend http://127.0.0.1:8080 -authSocket $socket_path/gitlab.socket -documentRoot $app_root/public"

Some output / logs:

Service Status:

# service gitlab status
The GitLab Unicorn web server with pid 13961 is running.
The GitLab Sidekiq job dispatcher with pid 14019 is running.
The gitlab-workhorse with pid 13992 is running.
GitLab and all its components are up and running.

Gitlab Check:

# sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production
Checking GitLab Shell ...

GitLab Shell version >= 2.6.10 ? ... OK (2.6.10)
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
hooks directories in repos are links: ...
Mikaël Capelle / test ... ok
Mikaël Capelle / test2 ... repository is empty
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 2.8.17
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 Reply by email ...

Reply by email is disabled in config/gitlab.yml

Checking Reply by email ... Finished

Checking LDAP ...

LDAP is disabled in config/gitlab.yml

Checking LDAP ... Finished

Checking GitLab ...

Git configured with autocrlf=input? ... yes
Database config exists? ... yes
Database is SQLite ... no
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config outdated? ... no
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory setup correctly? ... skipped (no tmp uploads folder yet)
Init script exists? ... yes
Init script up-to-date? ... no
  Try fixing it:
  Redownload the init script
  For more information see:
  doc/install/installation.md in section "Install Init Script"
  Please fix the error above and rerun the checks.
projects have namespace: ...
Mikaël Capelle / test ... yes
Mikaël Capelle / test2 ... yes
Redis version >= 2.8.0? ... yes
Ruby version >= 2.1.0 ? ... yes (2.1.6)
Your git bin path is "/usr/bin/git"
Git version >= 1.7.10 ? ... yes (2.1.4)
Active users: 2

Checking GitLab ... Finished

Gitlab-Workhorse logs:

# tail log/gitlab-workhorse.log
2016/01/26 17:51:49 Starting gitlab-workhorse 0.5.4-20160126.133734
127.0.0.1:8181 127.0.0.1:56838 - - [2016-01-26 17:52:51.436235423 +0100 CET] "GET /gitlab/mikael/test.git/info/refs?service=git-upload-pack HTTP/1.1" 401 0 "" "git/1.9.5.msysgit.0" 0.085899
127.0.0.1:8181 127.0.0.1:57006 - - [2016-01-26 17:52:57.24196212 +0100 CET] "GET /gitlab/mikael/test.git/info/refs?service=git-upload-pack HTTP/1.1" 401 0 "" "git/1.9.5.msysgit.0" 0.056232
127.0.0.1:8181 127.0.0.1:57009 - - [2016-01-26 17:52:57.332691334 +0100 CET] "GET /gitlab/mikael/test.git/info/refs?service=git-upload-pack HTTP/1.1" 200 70 "" "git/1.9.5.msysgit.0" 0.304730
127.0.0.1:8181 127.0.0.1:57025 - - [2016-01-26 17:52:57.670625801 +0100 CET] "GET /gitlab/mikael/test.git/HEAD HTTP/1.1" 404 9 "" "git/1.9.5.msysgit.0" 0.219617

I am using Apache 2.4 and Gitlab 8.4.1.