SWI-Prolog
		   (Frequently) Reported installation problems

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# gcc 2.5.[0123] optimiser bug

Diagnostic: [PROLOG INTERNAL ERROR: Unexpected signal: 11 ...]
Fixed from: gcc-2.5.4

All these versions of gcc produce bad  code on pl-wam.c.  Either upgrade
gcc or do

	% gcc -c pl-wam.c
	% make

Not optimising pl-wam.c degrades  performance  by   about  30%  on  most
machines.

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# PC/Linux libc 4.5.x change

Diagnostic: Compiler fails on pl-os.c
Fixed from: 1.8.7

Add the following line to src/md-linux.h:

#define RESET_STDIN		rewind(stdin)

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# Mixed BSD/POSIX signal handling

Diagnostic: Typing ^C twice kills Prolog, so does profiling and versions
using dynamic stack-expansion crash  on  a   segmentation  fault  at the
second expansion.

Make sure #define O_SIG_AUTO_RESET is set to 1.

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# Make fails on directory startup

Diagnostic: ../startup: no such file or directory

You probably didn't edit config.h, notably the variables M_SYSTEMHOME
and M_BINDIR should be edited to meet your system setup.

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# RS6000 AIX-3.2

Diagnostic: pl is killed during the boot compilation (pl -O -o ... -b ...
as run by make).

It appears linking `-static' does not work properly.  Use dynamic linking,
but explicitely link /usr/lib/libc.a as the last file to get saved states
working properly.

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# Readline version problems.

Diagnostic: generally the compiler bumbs out on pl-os.c with messages
related to rl_<something> symbols.  If you use librealine version 1.2,
you need #define O_RL12 1 in your md.h file for version 1.1, no such
line should be there.

Make sure readline is compiled with gcc if you compile SWI-Prolog
with gcc.  Make sure not to use BSD comapatibility for compiling
the readline library (signal handling problems).  This applies to
any foreign library you link to SWI-Prolog.