How to disable sandbox testing on Firefox startup
I found that when starting Firefox on my school's WiFi, it starts up very slowly. Using `strace`, I found that it was taking it's sweet time making a DNS request to try to resolve my computer's `/etc/hostname`. After searching the Firefox source code with https://searchfox.org/mozilla-central/source/, I found that the only occurrence of `/etc/hostname` was in [SandboxTestingChildTests.h](https://searchfox.org/mozilla-central/source/security/sandbox/common/test/SandboxTestingChildTests.h). So I was wondering if it's possible to disable these tests when Firefox starts up.
Wšykne wótegrona (1)
Those files in a test directory are only to ensure that Firefox is working properly and test a lot of features to make sure that everything works. Those tests aren't run in the normal use case, but are part of the compilation process, so if it hangs with the sandbox for you then you may have a problem with accessing some system data due to sandbox restrictions.
You can try Firefox from the official Mozilla server if you currently use a version from the repositories of your Linux distribution to see if it behaves differently.