Question

I have a 32bit architecture so I must build opa from source.

Configure works fine:

./configure -ocamlopt /opt/opa/bin/ocamlopt.opt -ocamlfind /opt/opa/bin/ocamlfind

Checking your OS... Linux
Checking your architecture... ix86
Checking ocamlopt... /opt/opa/bin/ocamlopt.opt
Checking ocamlbuild... /opt/opa/bin/ocamlbuild
Checking ocamldir... /opt/opa/lib/ocaml
Checking ocaml version... 3.12.0
Checking your ocaml setup... 3.12.0, Unix 32bit
Checking for camlp4... /opt/opa/bin/camlp4o
Checking for perl 5... found
Checking for camlidl... /opt/opa/bin/camlidl
Checking libnatpmp... /opt/opa/lib/ocaml/libnatpmp.a, OK
Checking miniupnpc... /opt/opa/lib/ocaml/libminiupnpc.a, OK
Checking for ocamlfind... /opt/opa/bin/ocamlfind
Checking for ssl... ocamlfind:/opt/opa/lib/ocaml/ssl, OK
Checking for cryptokit... +cryptokit, OK
Checking for camlzip... +camlzip, OK
Checking for graph... +ocamlgraph, OK
Checking for ulex... +ulex, OK

Congrats, you're all set. Installation will be done in:
/usr/local

Make returns:

make

Ocamlbuild plugin generation

_build/myocamlbuild -no-plugin -j 6 -tag debug pplib/ppml.native
ocamlbase.top libbase/ocamlbase database/database_server.native
jslang/jsstat.native database/database_tool.native
opatop/opatop.native passlib/opatrack.sh qmlcompilers/qmljs_exe.native
compilerlib/opadep.sh opabsl/opabslgen.bypass tools/odep.native
libbase/testfilepos.native opabsl/serverLib.cmi tools/odeplink.native
protocols/genproto.native libbase/bslServerLib.ml
opalang/opa2opa.native protocols/mlidl.native
tools/jschecker/compiler.jar tools/ofile.native
protocols/wsdl2ml.native dissemination/spawn.sh opa/main.native
bash_completion opadoc/opadoc.native pplib/ppopa.native
pplib/ppjs.native libbase/gen_platform teerex/trx_ocaml.native
teerex/trx_interpreter.native libbsl/bslregister.native
libbsl/bslbrowser.native libbsl/bslbrowser passlib/passdesign.native
opa-packages.stamp

+ /opt/opa/bin/ocamldep.opt -pp '/opt/opa/bin/camlp4o -I +ulex pa_ulex.cma pr_o.cmo'   -modules libbase/indexer.ml > libbase/indexer.ml.depends
Camlp4: Uncaught exception: DynLoader.Error ("pa_ulex.cma", "file not found in path")

Preprocessing error on file libbase/indexer.ml
Command exited with code 2.
Compilation unsuccessful after building 208 targets (204 cached) in 00:00:04.
make: *** [all] Erreur 10

Answer 1

Sorry but OPA doesn’t support 32 bit architecture for the moment.
We are working on it.

You can read this article we posted on our blog, we answered to this question (and others):
http://blog.opalang.org/2011/07/readers-questions-1.html

Q: Lack of 32-bit and Windows versions of the compiler

A: Yup, we’re guilty here. We’re working on the 32-bit version and
hope to have it ready within a couple of weeks. Windows version is
slightly more tricky but we did have a working Windows version and we
will have it again without a doubt. We could use some help, by the
way. Now that Opa is open-source. Any volunteers?

Keep in touch!