[Pkg-opencl-devel] pocl / LLVM versions

[Rebecca N. Palmer]

On 23/04/16 10:37, Giuseppe Bilotta wrote:
 > * all ICDs based on LLVM have to be built using the same version of
 > LLVM, or one will get random crashes and segfaults during execution;
 > this means that Pocl must be built with the same LLVM as
 > mesa-opencl-icd and beignet;

While Debian mesa uses 3.7, Ubuntu mesa uses 3.8, and I'm not yet sure 
whether beignet can use 3.8 (there's a patch to do so in upstream git, 
but it won't simply apply to the released version).

We'd also have to either have separate Debian and Ubuntu versions, or 
build-depend on both 3.7 and 3.8 and have debian/rules choose which gets 
used (perhaps after checking what mesa depends on, so we can't forget to 
change it?).

(Might https://bugs.launchpad.net/ubuntu/+source/beignet/+bug/1559605 
have been related to this?  Though it's now gone away, with mesa having 
been updated but not changed its LLVM version...)

----------

Ubuntu now allows build-depends from main(supported) to 
universe(unsupported) 
https://lists.ubuntu.com/archives/ubuntu-devel-announce/2016-April/001179.html 
; hence, it now has mesa-opencl-icd, and packages in main would be 
allowed to build-depend on pocl-opencl-icd to allow running OpenCL-using 
test suites.  However, runtime Recommends from main to universe (i.e. 
our proposed ocl-icd-libopencl1 -> opencl-icd-all -> *-opencl-icd) are 
still forbidden.  (clang was rejected for Ubuntu main due to #797917.)