Random stuff happens, Git 2.10.0 git-bash window does not draw any content at all anymore

0.4.11-RC-33-gb27a643 gcc dbg linux.
Git 2.10.0 from rapps.
VBox 4.3.12 + VBEMP
It happens with both: inbuilt Mesa and also if Mesa from rapps would be installed.

Reproductiion steps
-install Git
-start from startmenu "Git Bash"

Expected result
-a cygwin based window opens up and draws contents in text-mode, like xpsp3_gitBash.png

Observed result
-the window does not draw any content at all anymore.
0.4.11-RC-33-gb27a643__gitBash.png
0.4.11-RC-33-gb27a643__gitBash.log

Although I observed in older ticket CORE-15146 it did still draw stuff for me in that window using 0.4.10-RC-29-gf6a9392 gcc dbg lin, VBox 4.3.12, VBEMP.
I still do not longer believe this being a regression after performing some regression-testing
Especially the last 3lines in CORE-15688_gitBash_regressionTest.txt make me think that we observe somethin totally random here, that can not be properly regression-tested!
Maybe the git-setup seriously corrupts something in ros, or the drawing in git-bash is timing-related.