Cannot sseem to include libraries on different drive about hi-tech-z80-c HOT 1 CLOSED

The command line argument parser is rather primitive for CP/M and uses a space
as a delimiter.

To specify an include location, don't prefix it by a space - for example

c -i0:a: -o -v test.c

By default, the compiler will look in user area 0 on drive A: for the system include
files and object libraries.

You can also create a file called ENVIRON. on the source-file drive to override
the default, or have a system-wide one in 0:A:ENVIRON..

This file may contain lines like the following to specify the location of the
HI-TECH files - for example

HITECH=0:C:
TMP=M:

for distribution files on drive C: in user area 0, (and to create temporary
files on a RAMdrive - drive M: . NB; you can't specify a user area for TMP).

Details are in the Users Manual at
https://github.com/agn453/HI-TECH-Z80-C/blob/master/doc/Hi-Tech-Z80-1989-october.pdf
in section 1.6 Reconfiguring.

P.S. You didn't specify which version of CP/M you are using. With CP/M Plus you can
use the SETDEF command to set a search path for commands so you won't need to
specify the drive letter to invoke the compiler.

from hi-tech-z80-c.