Re: How to use INSTALL_LOCATION with system directories

[Ralph Lange via Tech-talk <tech-talk at aps.anl.gov>]

On Tue, 10 Oct 2023 at 10:21, Lucas Russo via Tech-talk <tech-talk at aps.anl.gov> wrote:

Regardless of the location our sites decide, does it make sense to try

to support that use case straight out of the box (box = epics base makefile rules)?

I don't really care about the staging area, that being out of source build or not,

so INSTALL_LOCATION could be $(TOP) or something I have write access to,

that is fine. I think I'm just concerned with the final installation step or FINAL_LOCATION,

from what I understand now.

So, does it make sense to add or split rules in EPICS base (maintaining

backwards compatibility) to provide that?

Something like:

make build

sudo make FINAL_LOCATION=/opt/test install

Or whatever target name to compile and one target for installing the binaries/libs/etc?

You do have a point there.

Classical open-source answer, then: The developers will be happy to review your PR. :-)

Be aware that EPICS has a number of quirks, though: tools being generated, header files being generated, such things.

Shouldn't make it impossible, but if you split build and install, the build of Base, e.g., while using the same Make rules, can't use locally created tools using the installation path, while building any downstream support modules needs to use Base's (installation) path for the same tools.

One thing is certain: You will learn a lot about how the EPICS Build system internally works, which - when working with EPICS - is a valuable thing.

Cheers,
~Ralph