This fixes issue #239 related to building Ruby on FreeBSD systems

[kaspergrubbe]

This relates to issue #239 that caused Ruby-build to fail when building Ruby on FreeBSD systems.

I tracked down the error, and it was caused by running make with the make -j 2-parameter.

Why it failed I don't know, but it would seem that using -j is disabling backwards compatibility, from the make man-page:

-B:
Try to be backwards compatible by executing a single shell per
command and by executing the commands to make the sources of a
dependency line in sequence. This is turned on by default unless
-j is used.

-j max_jobs
Specify the maximum number of jobs that make may have running at
any one time. Turns compatibility mode off, unless the -B flag
is also specified.

Before my change, running rbenv install 1.9.3-p327 ran make -j 2 would cause the compiling to fail:

installing default wait_for_single_fd libraries
compiling wait_for_single_fd.c
linking shared-object -test-/wait_for_single_fd/wait_for_single_fd.so
make: don't know how to make ../../.ext/common/bigdecimal. Stop
*** [ext/bigdecimal/all] Error code 2
1 error
*** [build-ext] Error code 2

After my change, the build would complete with make -B -j 2.

I don't know if my solution is the "prettiest", but maybe we should consider just adding the -B argument on other non-freebsd systems as well.

Thoughts about this?

[fabiankrack]

Alternatively you can use GNU make which most other system use as 'make'.

[kaspergrubbe]

Yep, that could be a nice solution, and wouldn't cripple other systems.

Some troubles between versions:

On FreeBSD:

[ben2@pregl ~]$ make --version
make: illegal option -- -
usage: make [-BPSXeiknpqrstv] [-C directory] [-D variable]
    [-d flags] [-E variable] [-f makefile] [-I directory]
    [-j max_jobs] [-m directory] [-V variable]
    [variable=value] [target ...]
[ben2@pregl ~]$ make -V MAKE_VERSION
5200408120

On OSX:

[~]=> make --version
GNU Make 3.81
[~]=> make -V MAKE_VERSION
make: invalid option -- V

It could be nice to rely on output from --version, but we have to be more sneaky. We could rely on the status code from each command and guess the proper version from the output, but I don't know how many different make-systems that we should support.

[kaspergrubbe]

I've made it available to guess which version is available based on argument detection. It is the following that is happening:

make --version       &>/dev/null ; PROBE_GCC_MAKE=$?
make -V MAKE_VERSION &>/dev/null ; PROBE_BSD_MAKE=$?

if [ $PROBE_GCC_MAKE -eq 0 ]; then
    echo "you have gcc make"
elif [ $PROBE_BSD_MAKE -eq 0 ]; then
    echo "you have bsd make"
fi

On my FreeBSD server:

[ben2@pregl ~]$ bash te.sh
you have bsd make

On my OSX Machine (it is the same on my Linux server):

[~]=> bash te.sh
you have gcc make

[sferik]

I believe this is problem is resolved by #272. If not, please reopen it.