I came across this PDP-11 version.  I saved it to the side while I was looking for my main target.

Now I’ve tried to compile it on contemporary UNIX of the time, namely Unix v7, 2.9 BSD and 2.10 BSD and they fail at the same point:

hack.monst.c:99: Too many initializers: mon
*** Error code 1

Stop.

What is more weird is I didn’t see anyone having any reports of it working, just requests for the code.  Although I have been able to compile and run it on 4.2BSD/VAX.  So it must be a cc/pcc thing, or some other C compiler they are using on the PDP-11 in Amsterdam circa 1985.  And then I found this interesting bit:

Date-Received: Mon, 22-Apr-85 06:57:56 EST
References: <[email protected]>
Reply-To: [email protected] (Andries Brouwer)
Distribution: net
Organization: CWI, Amsterdam
Lines: 11

In article <[email protected]> [email protected] (Chuck McManis) writes:
>… about the PDP-11 version of hack …
>All in all it doesn’t seem to do 90% of the things that make it different
>from rogue.

The PDP-11 version of hack is a slightly improved (by people at the VU,
Amsterdam) version of some code that was stolen from my directory
some three years ago; it was being worked on, and certainly not in a
shape fit for distribution. Thus, as you noted, it doesnt have half
of the features present in hack, and, what is worse, it is very buggy.
I am sorry it was distributed.

Which to me is kind of interesting as this recently happened on September 21st:

The NetHack Development Team feels it is necessary to publicly address an issue that has surfaced in the last week.

Recently a NetHack source distribution has appeared, claiming to be NetHack 3.5 or 3.5.0 or 3.4.4.

This claim is partially correct. This is our code. However it was not released by us or with our authorization. This code is not ready for release: it is unfinished, unpolished, and almost certainly very buggy. It has not been play-tested for balance or functionality. It is best considered a partial and unfinished rough draft. We will not be supporting this code, nor will we be releasing binaries or bugfixes for it. It will not be available through our website.

Due to this incident and to prevent confusion, we will not now nor in the future release anything with a version number of 3.4.4, 3.5, or 3.5.0.

We thank those of you who play and develop both NetHack and its many variants for your support and encouragement at this time and over the many years NetHack and its progeny have and continue to evolve.

So yeah it seems there is a long history of hacking hack, why even the Fortran port of Zork was born that way:

Zork (was) only as encrypted files that were runnable in an MDL environment but were not readable (and modifiable) as source code. They even went so far as to patch their famously insecure ITS development system, adding security to just the directory that stored the source. Hackers, however, won’t be denied, and soon one from DEC itself had penetrated the veil. From Infocom’s own official “History of Zork“:

[The security] was finally beaten by a system hacker from Digital: using some archaic ITS documentation (there’s never been any other kind), he was able to figure out how to modify the running operating system. Being clever, he was also able to figure out how our patch to protect the source directory worked. Then it was just a matter of decrypting the sources, but that was soon reduced to figuring out the key we’d used. Ted had no trouble getting machine time; he just found a new TOPS-20 machine that was undergoing final testing, and started a program that tried every key until it got something that looked like text. After less than a day of crunching, he had a readable copy of the source. We had to concede that anyone who’d go to that much trouble deserved it. This led to some other things later on.

Indeed,hackers won’t be denied.