Re: installing synApps on Ubuntu

["Johnson, Andrew N. via Tech-talk" <tech-talk at aps.anl.gov>]

Hi Randall,

On Aug 20, 2020, at 12:52 PM, Randall Cayford via Tech-talk <tech-talk at aps.anl.gov> wrote:

I found the problem.  The defaults for tar on centos 7 and Ubuntu 18 are different.  On centos, untaring synApps assigns the user who untars.  On Ubuntu (at least with the parameters I used) the assigned user appears to be the uid and gid of whoever created it.  I don’t know why compiling as root has a problem with this but the depends.pl script hangs in that case.  chown fixed the problem.

It seems to be accepted wisdom nowadays to *never* compile code as root, please do that as a regular user. By using root you are trusting that nobody who has write access to your compiler, linker, GNUmake, the application build system and any tools that it might use (including all the EPICS and synapps developers) has let in some malicious code that looks to see if it’s being run as root and tries to then turn your machine into a bot. Not recommended.

I have mostly successfully compiled synApps on Ubuntu now.  The dxp module won’t compile over some problem with finding functions in what appears to be libusb.  That one I haven’t solved.

As pointed out recently in a different thread, there are two different libusb APIs with different versions, if the code looks for libusb-1.0 make sure you have that and not the other one.

- Andrew

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