standard_init_linux.go:211: exec user process caused "exec format error"

[mattguide]

I am trying to build this image, and I am getting this error appearing at step 3, run apk: standard_init_linux.go:211: exec user process caused "exec format error"

I am using Linux (x64) with Docker version 19.03.13, build 4484c46d9d.

I have read that it may be due to mismatched architecture (x86-64 trying to run ARM image), and I think that may be the case. But it looks like I am using your AMD64 code.

If I am using the wrong architecture, how can I test that? Thanks in advance!