Some tests are stubborn and refuse to run from wrapper, e.g. tcsh test suite. See Bug 598895.
Instead of fighting them individually, provide environment as close as possible to original.
This will also provide a script with all env.variables required by the test.
Not 598895 but Bug 607994#c3 re: /CoreOS/tcsh/Sanity/upstream
Also the tcsh test suite is working well with this tweak. See https://beaker.engineering.redhat.com/recipes/49765.
The last run is with compatibility mode. The last but one is without it.
Going on with testing.
This works and fixed the reported compatibility issues I was aware of.
FYI, this requires to pass param
<param name="RHTS_OPTION_COMPATIBLE" value="yes"/>
to tasks to run in compatible mode. Bug 645769 should remove this necessity.