NPQ-rx is a bootstrapped compiler, which means that it uses itself to compile itself.
To make the first compilation possible,
a compiled version of the compiler is stored in /src/stage0/*.pir and included in the source code repository.
Also the parrot virtual machine ships the same
When you make changes to the compiler, eventually you need to update these stage0 files.
Here is how you proceed to update the bootstrapping files nqp-rx and parrot.
At any stage,
make test fails,
don't go ahead with the following steps,
but fix the problem first.
cp src/stage0/*.pir $PARROT_SRC/ext/nqp-rx/src/stage0
make testand commit