Can't we use Tempfile for this job like so (or similar):

Tempfile.open("#{@prefix}.rb_const_gen_bin") do |bf|
  binary = bf.path
  [...]

Can't we use Tempfile for this job like so (or similar):

Tempfile.open("#{@prefix}.rb_const_gen_bin") do |bf|
  binary = bf.path
  [...]

thanks for quick response!

As I understood, we need two files - one for generated c source code and another for binary (which is created by gcc)
first one used as you suggested
https://github.com/ffi/ffi/pull/929/files#diff-4756902fc04469bc839933537bb1bda3bbc1260617e86e215a587bfba0873bcdR128
but main assumption here, that no one is going to create same binary at the end of compilation (because of different process id), but inside docker you start with the process pid 1 and if you share tmp directory that leads to errors :(

Can't we use Tempfile for this job like so (or similar):

Tempfile.open("#{@prefix}.rb_const_gen_bin") do |bf|
  binary = bf.path
  [...]

maybe I misunderstood you, I did it in a different way, wdyt?

This looks good. Thank you!