bug#68151: automake-1.16j on Alpine Linux

[Bruno Haible]

On Alpine Linux 3.18, "make check" shows 167 test failures. All of them
have the same cause:
  gzip --best ...
fails because gzip is from BusyBox 1.36.1 and
  - does not understand the option '--best', only '-1' ... '-9'.
  - understands the options '-1' ... '-9' only when compressing, not when
    decompressing.

Find attached the log file.

This issue has already been seen by a GNU package (parted):
https://fossies.org/linux/gparted/ChangeLog line 1561.

Here's a proposed fix. It consists in passing '-9' instead of '--best'.
(gzip is 30 years old; it's extremely unlikely that it gets more
compression levels in the future.)
Also it removes the use of $(GZIP_ENV) when decompressing, since it causes
an error with BusyBox gzip and is redundant with GNU gzip.

test-suite.log.xz
Description: application/xz

0001-Fix-make-check-failures-on-Alpine-Linux-where-gzip-i.patch
Description: Text Data