I'm looking at the C translation, pretty the test suited areto blame. Made a C solution myself, it was consistently crashing on one particular "random" test, after quite a bit of head-scratching and poking with a stick, I found what seems to be a fix - it's calling an assert method with an output format string and 3 strings to plug into it - the complete, 100000-byte bf program, plus both the actual and expected c programs. After dropping those inserted values, all tests pass.

Not sure if this is the cause of any or all the problems or not. Hopefully a fix will be coming soonish, though!

language?

Be sure you do not print ANYTHING to the console, because it may produce this type of problems, considering the size of the inputs. Avoid recurcive solutions too, for the same reason.