more robust check of ISABELLE_PLATFORM_FAMILY within settings environment, to support its reunification with Isabelle/Scala (see also a33a6e541cbb, f3a356c64193);
#!/usr/bin/env bash
#
# Author: Makarius
#
# DESCRIPTION: setup OCaml via OPAM
set -e
if [ -d "$ISABELLE_OPAM_ROOT/$ISABELLE_OCAML_VERSION/bin" ]
then
isabelle_opam switch -y "$ISABELLE_OCAML_VERSION"
elif [ -e "$ISABELLE_OPAM_ROOT/config" ]
then
isabelle_opam switch create -y "$ISABELLE_OCAML_VERSION"
else
mkdir -p "$ISABELLE_OPAM_ROOT"
cd "$ISABELLE_OPAM_ROOT"
isabelle_opam init -y --disable-sandboxing --no-setup --compiler="$ISABELLE_OCAML_VERSION"
fi
isabelle_opam install -y zarith