User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

First noticed on Firefox 88, also occurs in Firefox Developer Edition 89 (firefox-developer-edition 89.0b1-1). Occurs on a clean install immediately after refreshing Firefox. I have reverted to Firefox 87 (firefox 87.0-2 on Arch) which does not have the issue.

1. Open godvillegame.com and log in.
2. Spend between 10ish minutes watching your hero.

I believe I've actually seen this happen with other sites as well, but godville seems to trigger it consistently and (relatively) quickly.

Actual results:

The tab goes blank, any new tabs opened will also be blank. If Firefox was started from a terminal a number of warnings along the lines of "WARNING: failed to create memfd: Too many open files: file /build/firefox-developer-edition/src/firefox-89.0/ipc/chromium/src/base/shared_memory_posix.cc:305"

Expected results:

Firefox should have continued to function as normal.

The Bugbug bot thinks this bug should belong to the 'Core::IPC' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Up until this point I've been using Firefox with MOZ_WEBRENDER=1. I've switched to MOZ_WEBRENDER=0 and have been using it the last few days without issue.

Before doing this I also tried and failed to replicate it on any other site and was unable to, so far it appears that I can only make this happen in Godville.

We had a file descriptor leak on Linux that caused a number of intermittent fd exhaustion bugs like this. I'll mark this as a duplicate; reopen if it's still happening.