The ConfigRegression build on Musca_A platform interrupts after boot and initialising the secure image. It doesn't perform the regression tests anymore.
The last working patch is: https://review.trustedfirmware.org/c/trusted-firmware-m/+/1559
The next patch (https://review.trustedfirmware.org/c/trusted-firmware-m/+/1560) doesn't compile because of an incorrect return type. The patch that fixes the incorrect return type is https://review.trustedfirmware.org/c/trusted-firmware-m/+/1602, but the ConfigRegression build is broken.