GenerateLDFlags function doesn't work on OSX

[rappizs]

The getBuildDateTime helper function, which is called by mage.GenerateLDFlags, doesn't work under OSX. The date command is a little bit different on OSX than on Linux and doesn't support the -d flag, therefore on OSX we get this error when trying to use mage.GenerateLDFlags: date: illegal option -- d

The exact problem is here:

release-utils/mage/version.go

Line 62 in 1bf6b4c

date, err := shx.Output("date", "-u", "-d", sourceDateEpoch, "+%Y-%m-%dT%H:%M:%SZ")

[saschagrunert]

Hm, we can probably generate the date from native golang libraries other than relying on GNU date.

[rappizs]

Already created a fix for it using GNU date: rappizs@e925304, but I agree that maybe some native go solution would be better.

[saschagrunert]

Yeah, like this: #91

[rappizs]

Awesome, thanks for the quick fix @saschagrunert!

[justaugustus]

Thanks @saschagrunert!