Package: firefox-esr Version: 52.5.3esr-1 This is the second version of firefox-esr in a row which has a build-failure on ppc64el, meaning that this package cannot migrate to testing. There was a security fix in 52.5.2esr-1, so it would be very good to attempt to address this.
Sadly, I don't have any idea how the firefox build works or what might be causing the problem, so I don't know how to help fix this one. Best wishes, Julian