runtime.CallersFrames is undefined

[greenpau]

Received the following error:

vendor/go.uber.org/zap/stacktrace.go:63: undefined: runtime.CallersFrames

The issue is with this line:

    frames := runtime.CallersFrames(programCounters.pcs)

Go version:

$ go version
go version go1.6.3 linux/amd64
$

[greenpau]

When I commented out the runtime code, I got the error I was looking for:

log.Infof undefined (type *zap.Logger has no field or method Infof)

[akshayjshah]

Hi @greenpau - thanks for including your Go version in the issue.

Zap only supports the current stable Go release and one previous release; right now, that's 1.7 and 1.8. Since the CallersFrames API was added in 1.7, zap won't work properly on 1.6.

[akshayjshah]

Added a note about version support in the README (see #391).