If your IP (and possible your browser) looks “suspicious” or has been used by other users before, you need to add additional information for registration on gitlab.com, which includes your mobile phone number and possibly credit card information. Since it is not possible to contribute or even report issues on open source projects without doing so, I do not think any open source project should use this service until they change that.
Screenshot: https://removed/XsfcfHf/gitlab.png
Linus accepted patch from literal child. But to be fair it was documentation style patch from one of kernel dev’s kid.