Subject: Compiling PM3 Modula-3, worked under B20.0, now hangs "rm", "as", others in infinite loop on B20.1
From: "Parzival Herzog" <[email-masked]>
To: <[email-masked]>
Cc: "Michel Dagenais" <[email-masked]>
Date: Tue, 9 Mar 1999 00:58:42 -0600

I had used B17-19 with no problems for months, Then before I installed PM3 Modula-3,
I updated to B20.0. PM3 Modula-3 (http://polymtl.ca/m3) installed and ran successfully,
then updated to B20.1. PM3 Modula-3 and Cygwin appeared to work fine. Then I tried
to compile a large Modula-3 package, and after compiling part-way through the
system, my computer hung in an infinite loop, steadily allocating about 50-60K of
memory per second, with 100% CPU utilization, and no significant disk activity. At first
I thought this was a Modula-3 problem, but gradually started to suspect it was a timing
problem in the Cygwin library. I noticed that the hang occurred after approximately the
same amount of elapsed time compiling, and not on the same source file, and with
exactly the same behaviour while several different programs were active, i.e. M3cgc1 (the Modula
3 compiler), as (the GNU assembler - called by the compiler), and even once in "rm" (the Cygwin
rm program.)

So, I decided to rebuild from scratch the Modula-3 compiler. This failed in exactly the
same way, with a hang, not always on the same source file, but after roughly the
same amount of elapsed time well into a (very complex) build process. I then
uninstalled B20.1, and I went to fetch B20.0, but it was gone from the ftp sites.
(I  guess the "serious bug" fixed in 20.1 caused its withdrawal.) So I fetched and
installed B19.1 Now, Modula-3 installed and ran correctly, and all the systems
that failed to compile under B20.1, compiled correctly. 

Unfortunately, I can't boil this down to a simple isolated case: its not a specific
program that hangs, but an arbitrary program, and that program is spawned by
a (make-like) shell (m3build) executing a complex build operation. To reproduce
the problem you have to install PM3 Modula-3. And in order to do that you need
LOTS of disk space (about 400 MB) and you need a patch (at least for the
PM3 1.1.10 version - this may be fixed in the PM3 1.1.11 release - please
contact [email-masked]  . I can say that PM3 Modula-3 is very
reliable very portable software that installs and works on dozens of machines and
flavours of UNIX, and I hope the Cygnus developers will look into this problem relatively
quickly!

I have a Windows NT 4.0 system, service pack 4, on a 128MB AMD K6-266 machine,
I run the NTFS file system, with compression turned on.

Parzival