Frankie assures me that this is not a bug, but is the design of the server, intended to provide some level of security. I find it problematic in that hides the TCPIP environment variables from any other applications (SENDMAIL) I might be trying to run from a CGI script.
ScriptAlias /cgi-test/ p:/cgi-test/will return nothing, and cause an entry in the error log as follows:
os2httpd: malformed header from scriptduplicating the directory as E:\CGI-TEST and changing the entry to:
ScriptAlias /cgi-test/ e:/cgi-test/which works fine.
This bug is fixed by the current fix package: P_950307.