undefined: iofs.PartialDriver error on mysql tag

[cemezgin]

Describe the Bug
I am getting an error when I try to get mysql tag via go get.

Steps to Reproduce
Steps to reproduce the behavior:

1. I have this command in my Dockerfile RUN go get -tags 'mysql' -u github.com/golang-migrate/migrate/cmd/migrate
2. When I build it, see the error

Go Version
go version go1.13.15 linux/amd64

Stacktrace

> [8/8] RUN go get -tags 'mysql' -u github.com/golang-migrate/migrate/cmd/migrate:                                                                                                                                                     
#12 6.997 # github.com/golang-migrate/migrate/source/file
#12 6.997 ../../golang-migrate/migrate/source/file/file.go:17:2: undefined: iofs.PartialDriver

[robovarga]

Same problem

Go Version
go version go1.15.1 linux/amd64

[djhworld]

The iofs package has build constraints put in place to only build on go1.16+

https://github.com/golang-migrate/migrate/blob/master/source/iofs/iofs.go#L2

To resolve you can upgrade to go 1.16+ and also use the command highlighted in https://github.com/golang-migrate/migrate/tree/master/cmd/migrate#unversioned

EDIT: looks like this was introduced in 0775323 - this file references iofs.PartialDriver which if you try to build on < go1.16 it won't be present, causing the build failure.

Additionally looks like minimum support version for Go is now 1.16 df6106d

[Fontinalis]

As @djhworld said and pointed out, the minimum version for Go is now 1.16. Using the mentioned solution is a great way to resolve the issue.

On the same note, v4.15.0 was just released with the mentioned changes included.