Looks like the culpit is in postinst:
DEBIAN/postinst:EFIDIR=$(awk '/^ID=/ {gsub(/"/,""); split($$0,a,"="); print
tolower(a[2])}' /etc/os-release)
running the awk command gives the same output:
$ awk '/^ID=/ {gsub(/"/,""); split($$0,a,"="); print tolower(a[2])}'
/etc/os-release
awk: illegal field $(ID=debian), name "0"
input record number 4, file /etc/os-release
source line number 1
Looks like it has been copied from a Makefile, the $ is doubled, it should be:
EFIDIR=$(awk '/^ID=/ {gsub(/"/,""); split($0,a,"="); print tolower(a[2])}'
/etc/os-release)
which gives:
$ echo $EFIDIR
debian
--
[Julien Palard](https://mdk.fr)
