OK,
the custom modpack is located at:
http://www.technicpack.net/modpack/details/projectretv7.416090
The api URL is:
http://www.technicpack.net/api/modpack/projectretv7
Response after adding the modpack to the technic launcher is:
[B#441] InstalledPack{info=SolderPackInfo{name='projectretv7', display_name='ProjectRETv7', url='null', icon_md5='a5ea4c8fa53984c911a1b52ca31bc008', logo_md5='70a114d55ff1fa4c5eef7f2fdeeb7d03', background_md5='', recommended='', latest='0.0.1', builds=[0.0.1], solder=net.technicpack.launchercore.restful.solder.Solder@712911bd}, name='projectretv7', platform=true, build='recommended', directory='%MODPACKS%projectretv7'}
The Build (0.0.1) is also recognized by the launcher.
Then I press the play button an:
( Please submit this report to https://github.com/TechnicPack/TechnicLauncher/issues )
Launcher Build: 441
Selected Pack: null
Stack Trace:
Exception: NullPointerException
Message: null
Trace:
net.technicpack.launchercore.install.ModpackInstaller.installPack(ModpackInstaller.java:65)
org.spoutcraft.launcher.InstallThread.run(InstallThread.java:62)
System Information:
Operating System: Linux
Operating System Version: 3.12.13-gentoo
Operating System Architecture: amd64
Java version: 1.7.0_60 64 bit
Total Memory: 303 MB
Max Memory: 1714 MB
Memory Free: 77 MB
CPU Cores: 2
Sorry, that was my fault. There was no recommended build, and the launcher was looking for a recommended build. Now it is working.