Paul,
I have some vague memory of gsview using nmake rather than make.... perhaps try running nmake
Thank you (Thumbs-Up), because somehow I missed the following in the Readme.htm doc:
...
To compile GSview for OS/2 you need IBM NMAKE.EXE and EMX/GCC 0.9d. To create the GSview online help you need the IBM toolkit. Copy srcos2/os2.mak to Makefile and edit COMPBASE and EMXPATH as required. Type 'nmake'
...
Which now of course explains why there were multiple "!if" statements in the makefile and which GCC make.exe was choking on.
I had earlier assumed that the EMX requirements would be fulfilled by the current GCC RPM package releases, I say this because in the \usr\... tree there are multiple references to EMX objects. I do have exmrt.0.9d-5.oc00.i386 installed here, however I do not have the emxrt-devel.0.9d-5.oc00.i386 one.
Specifically, the EMX stuff I see is:
Directory of G:\usr\bin
8-26-21 9:13a 11,118 124 a--- emxaout.exe
8-26-21 9:13a 22,883 124 a--- emxbind.exe
8-26-21 9:13a 46,263 124 a--- emxexp.exe
8-26-21 9:13a 25,286 124 a--- emximp.exe
8-26-21 9:13a 6,289 124 a--- emxload.exe
8-26-21 9:13a 97,002 124 a--- emxomf.exe
8-26-21 9:13a 13,880 124 a--- emxomfar.exe
8-26-21 9:13a 42,417 124 a--- emxomfld.exe
8-26-21 9:13a 3,773 124 a--- emxomfstrip.exe
8-26-21 9:13a 4,260 124 a--- emxstack.exe
8-26-21 9:13a 9,209 124 a--- emxtsf.exe
11 file(s) 282,380 bytes used
...and as best as I can tell these all came from the libc-devel-0.1.9-1.oc00.pentium4 RPM package.
So in order to avoid future self-made problems

, what should I set COMPBASE and EMXPATH to?
Right now I have the makefile set to use:
...
COMPBASE=$(DRIVE)\usr
EMXPATH=$(DRIVE)\usr
...
Alright, so a little bit of un-do needed to get this moving...