Not a bug, but a feature request. (Yes, I know...)
In case of a crash the crash report is shown nicely in the launcher, but the Button "Report to Mojang" doesn't attach the crash report automagically. Since most users fail to attach the crash report or even fill out the optional fields ("Description") resulting in a flood of incomplete tickets here:
https://mojang.atlassian.net/issues/?jql=resolution%20%3D%20Incomplete%20AND%20text%20~%20%22without%20crash%20report%22%20ORDER%20BY%20key%20DESC
A compromise would be instead of attaching the crash report to embed it in the description envelopped by {code} tags.