Can the /tmp directory be changed for the shell-local post processor?

So I am trying to use the shell-local post processor to run a few commands after a build is finished. However, /tmp is mounted as noexec due to security. That isn’t really a problem, but even though when I remount /tmp with exec, the build fails like this:

==> qemu.image_build: Running post-processor:  (type shell-local)
==> qemu.image_build (shell-local): Running local shell script: /tmp/packer-shell903509056
==> qemu.image_build (shell-local): /bin/sh: /tmp/packer-shell903509056: Permission denied

This is strange as it was working fine the week before and nothing has changed. While SELinux is in enforcing mode, I set it to permissive just to test and sure enough, it will still fail.

Here is the post-processor block:

post-processor "shell-local" {
      inline = [
        "echo 'Copying ${local.image_family}-${var.build_number}.tar.gz to the ${var.gcs_bucket} bucket'",
        "gsutil cp output/${local.os}/${local.os}_disk.raw.tar.gz gs://${var.gcs_bucket}/${local.os}/${local.image_family}-${var.build_number}.tar.gz",
        "echo 'Creating ${local.image_family}-${var.build_number} image'",
        "gcloud compute images create ${local.image_family}-${var.build_number} \\",
        "--source-uri=gs://${var.gcs_bucket}/${local.os}/${local.image_family}-${var.build_number}.tar.gz \\",
        "rm -rf output"

Is there a way to redirect where packer is writing these temporary scripts for the shell-local post processor?

So apparently I am making this more complicated than necessary. I set TMPDIR=<some_dir> before executing the packer command and this allowed the process to run and execute files in a location other than tmp.