This hint most likely only applies to people who have installed or used Linux on an Intel-based Mac. If this is not you, you may want to stop reading now.
Anyway, if you have tried to edit a GPT partition map using GNU parted, or a utility that uses libparted, and if you’re not very good about following directions (like me), you may have accidentally set some of the partition “flags” that it exposes, such as msftres or boot. I put the term “flags” in quotes because it appears that parted actually changes the partition’s type in the GPT from whatever it was before to — in the case of msftres — a “Microsoft Reserved” partition (GUID E3C9E316-0B5C-4DB8-817D-F92DF00215AE). These can have some unintended consequences — as I found out, setting boot on any partition besides the EFI reserved one at the beginning of the disk will make any OS X installations on that disk unbootable.
Fortunately, b…
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