I'm stuck in a loop of "Sorry. We just need to do one small thing to keep going." and restarts.
I have spent hours on this and my seach-fu is not bad, bu to no avail.
It happened first after an update, and then with a fresh download of tor-browser-linux64-9.0.5_en-US.tar.xz. (I'm on Ubuntu 18.04) Help->About->version shows as up to date.
starting with the --verbose or --log flag puts out about 130 lines of messages with lots of warnings and errors, but I have no idea how many of these are just the usual "firefox-noise". I have searched for a lot of them and gone down a number of rabbitholes but ultimately came up empty handed.
I have also inspected the start-tor-browser script and tried to start the browser in different ways like running firefox.real, but nothing makes any difference to the behavior. (except if I break DISPLAY)
My current theory is that something makes an internal process crash and that is detected as if an external system has updated it's files.
I'd be happy to upload the log, but I understand that pestebin etc. is frowned upon.
Any help is appreciated.
For the record: Since I wrote the above, an OS update, a reboot and a browser update has happened and the issue just went away. I guess we'll never know exactly what caused it.
What I can report is where the failing and successful logs diverge.
Mar 11 07:59:58.000 [notice] Bootstrapped 100% (done): Done Unable to init server: Could not connect: Connection refused (/home/user/tmp/tor-browser_en-US/Browser/firefox.real:2985): Gtk-WARNING **: 07:59:59.408: cannot open display: :0 [Parent 2921, Gecko_IOThread] WARNING: pipe error: Broken pipe: file /var/tmp/build/firefox-869854aeea80/ipc/chromium/src/chrome/common/ipc_channel_posix.cc, line 727 [Parent 2921, Gecko_IOThread] WARNING: FileDescriptorSet destroyed with unconsumed descriptors: file /var/tmp/build/firefox-869854aeea80/ipc/chromium/src/chrome/common/file_descriptor_set_posix.cc, line 23
Mar 23 08:05:21.000 [notice] Bootstrapped 100% (done): Done Mar 23 08:05:21.000 [notice] New control connection opened from 127.0.0.1. Mar 23 08:05:21.000 [notice] New control connection opened from 127.0.0.1. Fontconfig warning: "/home/user/tmp/tor-browser_en-US/Browser/TorBrowser/Data/fontconfig/fonts.conf", line 145: blank doesn't take any effect anymore. please remove it from your fonts.conf
I would say this strongly point to an issue with "display" but I tried dozens of things with that, so who knows.