Created attachment 522414 [details] build.log The build log is cluttered with warnings, though I am uncertain what is the point of failure. Probably this: In file included from partgpt.c:45:0: common.h:128:2: error: initializer element is not constant ((efi_guid_t){le32(0x516e7cb4),le16(0x6ecf),le16(0x11d6),0x8f,0xf8,{0x00,0x02,0x2d,0x09,0x71,0x2b}}) ^
Created attachment 522416 [details] emerge --info
Just tried git-master. Despite a lot of warnings it builds fine.
I suspect that this upstream commit fixes the compilation failure: https://git.cgsecurity.org/cgit/testdisk/commit/?id=1c9b71e871d1d65cfe3e0cdbbcf362d2104801d9
app-admin/testdisk-7.1_pre20180322-r1 builds fine on ppc. Closing.