In #183 the definition of errors.Frame was altered to type Frame runtime.Frame. This was necessary because of the changes to mid stack inlining in Go 1.12 and the deprecation of runtime.FuncForPC.

https://go-review.googlesource.com/c/go/+/156364 suggests that it may be possible to continue to use runtime.FuncForPC. If this CL lands #183 should be mostly reverted for the 1.0 release.

A future v2 release would probably drop the use of runtime.FuncForPC and redeclare errors.Frame as an opaque struct.