[update: Joe Armstrong replied; see comments]

I’m having trouble running the lib_chan example from chapter 10 of Programming Erlang. Here’s what I’ve done, step by step. The console listings are from a machine running Ubuntu linux 7.04. I get similar results under OS X.

First, I downloaded the latest source code. 

drc@dawn:~/erlang$ wget http://media.pragprog.com/titles/jaerlang/code/jaerlang-code.tgz
--18:43:49--  http://media.pragprog.com/titles/jaerlang/code/jaerlang-code.tgz
           => `jaerlang-code.tgz'
Resolving media.pragprog.com... 207.7.108.187
Connecting to media.pragprog.com|207.7.108.187|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1,326,401 (1.3M) [text/plain]

100%[=========================================================================>] 1,326,401    402.03K/s    ETA 00:00

18:43:57 (341.37 KB/s) - `jaerlang-code.tgz' saved [1326401/1326401]

drc@dawn:~/erlang$ tar -zxf jaerlang-code.tgz
drc@dawn:~/erlang$ ls
code/  jaerlang-code.tgz

As per Joe’s suggestion here, I run make. 

drc@dawn:~/erlang$ cd code/
drc@dawn:~/erlang/code$ make
erlc -W a.erl
erlc -W b.erl
erlc -W checker.erl
./checker.erl:39: Warning: variable 'Arity' is unused
./checker.erl:73: Warning: variable 'T' is unused
./checker.erl:84: Warning: variable 'T' is unused
./checker.erl:97: Warning: variable 'A' is unused
erlc -W name_server1.erl
erlc -W test_mnesia.erl
erlc -W tracer_test.erl
cd socket_dist; make compile
cd: 1: can't cd to socket_dist
make[1]: Entering directory `/home/drc/erlang/code'
cd socket_dist; make compile

The error message starts looping, make is apparently unable to enter the socket_dist directory, so I ctrl-c out.
The directory does exist, and permissions look ok: 

drc@dawn:~/erlang/code$ ls -dl so*
drwxr-xr-x 2 drc drc 4096 2007-08-08 18:37 socket_dist/
-rw-r--r-- 1 drc drc 2664 2007-08-08 18:37 socket_examples.beam
-rw-r--r-- 1 drc drc 2608 2007-08-08 18:37 socket_examples.erl
-rw-r--r-- 1 drc drc  535 2007-08-08 18:37 sort.csv

I don’t know squat about make, but looking inside ./Makefile, these lines catch my eye:

compile: ${MODS:%=%.beam} subdirs trigramsOS.tab
        @echo "make clean - clean up"

shoutcast: compile
        erl -s shout start

subdirs:
        cd socket_dist; make compile
        cd escript-4.1; make

My first idea is to fully qualify socket_dist and escript-4.1. My guess is that should not be necessary, but what have I got to lose? I change the Makefile to read 

subdirs:
        cd /home/drc/erlang/code/socket_dist; make compile
        cd /home/drc/erlang/code/escript-4.1; make

and then run make again. 

drc@dawn:~/erlang/code$ make
cd /home/drc/erlang/code/socket_dist; make compile
make[1]: Entering directory `/home/drc/erlang/code/socket_dist'
mkdir -p /home/drc/.erlang_config/
cp conf /home/drc/.erlang_config/lib_chan.conf
make clean - clean up
make[1]: Leaving directory `/home/drc/erlang/code/socket_dist'
cd /home/drc/erlang/code/escript-4.1; make
make[1]: Entering directory `/home/drc/erlang/code/escript-4.1'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/home/drc/erlang/code/escript-4.1'
make clean - clean up

Well, that looks plausible, but I don’t understand why I had to edit the Makefile, and am not at all comfortable that this is going to work. I press on. 

drc@dawn:~/erlang/code$ cd socket_dist/
drc@dawn:~/erlang/code/socket_dist$ make
mkdir -p /home/drc/.erlang_config/
cp conf /home/drc/.erlang_config/lib_chan.conf
make clean - clean up
To run the chat test program
  1) start two xterms
  2) in xterm one type -- make chat_server
  3) in xterm two type -- make chat_client
  Note: remember to type make in the directory above this
        before running make in this directory
To run the lib_chan test program
  1) start two xterms
  2) in xterm one type -- make server
  3) in xterm two type -- make client

OK, I’ll try it. I want to run lib_chan, so I open another console. In the first console I run make server: 

drc@dawn:~/erlang/code/socket_dist$ make server
mkdir -p /home/drc/.erlang_config/
cp conf /home/drc/.erlang_config/lib_chan.conf
make clean - clean up
erl -pa ../ -boot start_clean -pa '.' -s lib_chan_test start_server
Erlang (BEAM) emulator version 5.5.2 [source] [async-threads:0] [kernel-poll:false]

lib_chan starting:"/home/drc/.erlang_config/lib_chan.conf"
ConfigData=[{port,1234},
            {service,nameServer,
                     password,
                     "ABXy45",
                     mfa,
                     mod_name_server,
                     start_me_up,
                     notUsed},
            {service,srpc,password,"secret",mfa,mod_srpc,start,[test1]},
            {service,root,
                     password,
                     "verySecret",
                     mfa,
                     mod_srpc,
                     start,
                     [any_apply]},
            {service,test1,password,"test1",mfa,mod_test1,start,{hi,joe}},
            {service,echo,password,"echo1",mfa,mod_echo,start,{server,args}},
            {service,math,password,"qwerty",mfa,mod_math,run,[]}]

That all looks in line with what the book leads me to expect. Now to run make client: 

drc@dawn:~/erlang/code/socket_dist$ make client
mkdir -p /home/drc/.erlang_config/
cp conf /home/drc/.erlang_config/lib_chan.conf
make clean - clean up
erl -pa ../ -boot start_clean -pa '.' -s lib_chan_test start_client
Erlang (BEAM) emulator version 5.5.2 [source] [async-threads:0] [kernel-poll:false]

test:1
Eshell V5.5.2  (abort with ^G)
1> received:"hello"
test:2
received:{chan,<0.37.0>,15511210043330985984000000}
test:3
E=:{error,badService}
test:4
E = {error,authFail}
test:5
F=2432902008176640000
test:6
F={'EXIT',{modNotAllowed,test2}}
test:7
F1=2432902008176640000
test:8

The two error msgs don’t inspire confidence. At this point, I have nothing. My results on OS X are pretty much identical. I had a passing thought that maybe some port was blocked, so I turned off the firewall (I am behind a NAT router, so it’s ok). It didn’t help. I posted to erlang-questions, but I often experience a day or two lag between the time I post and the time I see my question appear. Tick tock.