Hi!

With the upgrade to 9.24, the invocation of gs made by cups breaks, and generates a ps file on stdout containing spurious errors messages at the beginning of the file that probably should go to stderr instead:

[root@monkey tmp]# gs -q -dNOPAUSE -dBATCH -dSAFER -dNOMEDIAATTRS -sDEVICE=ps2write -dShowAcroForm -sOUTPUTFILE=%stdout -dLanguageLevel=3 -r300 -dCompressFonts=false -dNoT3CCITT -dNOINTERPOLATE -c 'save pop' -f /var/spool/cups/tmp/foomatic-gqB0dg > /tmp/file.ps
  ./base/gsicc_manage.c:1244: gsicc_open_search(): Could not find ps_gray.icc 
+ ./base/gsicc_manage.c:255: gsicc_initialize_iccsmask(): failed to load gray smask profile
  ./base/gsicc_manage.c:1244: gsicc_open_search(): Could not find default_rgb.icc 
| ./base/gsicc_manage.c:2025: gsicc_set_device_profile(): cannot find device profile
GPL Ghostscript 9.24: Unrecoverable error, exit code 1
  ./base/gsicc_manage.c:1244: gsicc_open_search(): Could not find default_gray.icc 
| ./base/gsicc_manage.c:2025: gsicc_set_device_profile(): cannot find device profile
[root@monkey tmp]# head -20 /tmp/file.ps
   **** Error reading a content stream. The page may be incomplete.
               Output may be incorrect.
   **** Error: File did not complete the page properly and may be damaged.
               Output may be incorrect.
   **** Error: Recursive XObject detected, ignoring "x8", object number 12
               Output may be incorrect.
Error: /rangecheck in .installpagedevice
Operand stack:
   true   --nostringval--   --dict:205/211(ro)(L)--   --nostringval--   --nostringval--   false
Execution stack:
   %interp_exit   .runexec2   --nostringval--   --nostringval--   --nostringval--   2   %stopped_push   --nostringval--   --nostringval--   --nostringval--   false   1   %stopped_push   2015   2   3   %oparray_pop   2014   2   3   %oparray_pop   1998   2   3   %oparray_pop   --nostringval--   1936   2   4   %oparray_pop   --nostringval--   1920   2   4   %oparray_pop   --nostringval--   --nostringval--
Dictionary stack:
   --dict:975/1684(ro)(G)--   --dict:1/20(G)--   --dict:78/200(L)--   --dict:78/200(L)--
Current allocation mode is local
%!PS-Adobe-3.0
%%BoundingBox: 0 0 595 842
%%HiResBoundingBox: 0 0 595.00 842.00
%%Creator: GPL Ghostscript 924 (ps2write)
%%LanguageLevel: 2
%%CreationDate: D:20180911143210+02'00'

The same command line on the same pdf file (the foomatic file is a pdf) with 9.23-6 works fine : no error message about icc profiles, and the generated file begins with "%!PS-Adobe-3.0" as expected.