I have tested manually - can not reproduce the trivial-features-tests load error on any ABCL.
It only happened during test-gird-testing, when output-pathname-translations were overriden to place all fasl file to a temp directory. Probably the error happaned due to some interaction between cffi-grovel, asdf output-translations and cl-test-grid overriding the translations.
I suppose my situation is unrelated the Maxima load error Robert Dodier reported.
Sorry for the noise. Please ignore the trivial-features-tests for now.
Best regards, - Anton