https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63622
--- Comment #9 from howarth at bromo dot med.uc.edu --- The darwin linker developer's analysis of this failing linkage is as follows... That link line contains “-undefined dynamic_lookup” which is almost always a bad idea. Removing it shows the problem. The symbol __ZTCSt9strstream16_So is not defined in an object file. So that option means “assume it will be in some dylib (DSO) at runtime). But the function __ZNSt9strstreamC1Ev contains: __ZNSt9strstreamC1Ev: ... 0000000000001f75 leaq __ZTCSt9strstream16_So+24(%rip), %rax … That code gen requires the target vtable to be in the same linkage unit, but is is in DSO. The only way to possible make it work is to have a text relocation which adjusts the LEA at launch time. But darwin x86_64 does not support text relocations. You should remove the “-undefined dynamic_lookup” from the link line and fix the build to have all required symbols defined.
