I received an error upon starting MakeMKV today to the effect that the version I had installed was too old, so I set about pulling in the latest version. Gentoo doesn't have an ebuild for v1.8.8, so I copied the v1.8.7 ebuild to my overlay and renamed it to pull in the newer version. It ripped a DVD OK, but two attempts at ripping Blu-rays failed with fatal errors before the track list became available. When I downgraded to v1.8.7, this crash didn't happen...so far, one of the two discs that failed with v1.8.8 is ripping without any issues I can see.
If it matters, the discs at issue are Star Trek, season 2, discs 2 and 3. That the older version of MakeMKV works and the newer one doesn't suggests that a bug was introduced in the newer version. My Gentoo overlay is at https://github.com/salfter/portage.