On Sat, Jun 03, 2023 at 08:12:48PM +0100, Christopher Baines wrote: > > Efraim Flashner writes: > > > On Fri, Jun 02, 2023 at 11:03:42PM +0100, Christopher Baines wrote: > >> > >> guix-commits@gnu.org writes: > >> > >> > efraim pushed a commit to branch master > >> > in repository guix. > >> > > >> > commit 076688fa1e41a09f034a80e1a593bac43f1f1482 > >> > Author: Efraim Flashner > >> > AuthorDate: Thu Jun 1 11:06:00 2023 +0300 > >> > > >> > gnu: openblas: Update architectures we provide substitutes for. > >> > > >> > * gnu/packages/maths.scm (openblas)[arguments]: Adjust the substitutable? > >> > flag to only not provide substitutes when building for powerpc-linux. > >> > Adjust the comment accordingly. > >> > --- > >> > gnu/packages/maths.scm | 11 ++--------- > >> > 1 file changed, 2 insertions(+), 9 deletions(-) > >> > >> I've been looking at why armhf-linux substitute availability has been > >> dropping recently, and I think this change triggered a lot of > >> rebuilds. Could this have gone to core-updates? > >> > >> → guix refresh -l openblas > >> Building the following 2282 packages would ensure 5596 dependent packages are rebuilt: ... > > > > It's not that it's triggered rebuilds, but that it's triggered builds. > > It's also triggered builds on powerpc64le and riscv64. Before any > > package which had openblas as a transitive dependency wasn't built by > > the CI because it wasn't substitutable¹. People still have the option of > > using package transformations to use openblas tuned for the cortex a7 or > > a15 on armhf, but in reality this just unlocks substitutes for those > > ~5600 packages which wasn't available before. > > > > ¹ We saw this in the past briefly in the past when openzfs made its way > > as a dependency to qemu and through that to Gnome. > > Ok, so the documentation does mention "rebuilding", and I do see that > indeed ci.guix.gnu.org doesn't build not substitutable things. > > Although I think it doesn't apply recursively. Take qjson, guix refresh > -l tells me it's dependent on openblas, and looking back at say this > output [1] for powerpc64le-linux, that's available from both > ci.guix.gnu.org. Which makes sense, as that derivation is substitutable, > even though one of it's inputs isn't. > > 1: https://data.guix.gnu.org/gnu/store/fibiwzyz8s899ccpix5zs6r2pcdpxk5b-qjson-0.9.0 > > Maybe on the client side this works differently, and guix won't > substitute things which have a non substitutable input? > > Assuming ci.guix.gnu.org was building things for armhf-linux, I think > this would have still caused ~5596 rebuilds, and as I say, I think for > systems like powerpc64le-linux, I think it did cause ~5596 > rebuilds. I looked into it more. First I ran on master: './pre-inst-env guix build --no-grafts --system=armhf-linux openblas -d' /gnu/store/whi4yhiw2b0c0i3n6l8s0qfcphkvbzg4-openblas-0.3.20.drv Then I locally reverted the patch expanding the architectures where we provided substitutes: /gnu/store/1m57z8jkbf6gz7qlbw3ws4ayl0ln9602-openblas-0.3.20.drv Then I locally reverted the patch adjusting the make-flags: /gnu/store/1m57z8jkbf6gz7qlbw3ws4ayl0ln9602-openblas-0.3.20.drv It seems I was wrong, changing the #:substitutable? flag _does_ change the derivation of the package. I also checked the substitutes and saw that bordeaux did (and does) have substitutes for the non-substitutable version, showing that it was built before. I also checked for powerpc64le, to see if perhaps cuirass worked a different way and honored the #:substitutable flag by not building it there, and it too has substitutes for both versions of openblas. I didn't check for riscv64 but I assume the case is the same with a changing derivation. So obviously if I had realized this would cause ~5596 rebuilds per affected arch I wouldn't have pushed the patch. I should've checked the derivation before and after to make sure it didn't change. -- Efraim Flashner רנשלפ םירפא GPG key = A28B F40C 3E55 1372 662D 14F7 41AA E7DC CA3D 8351 Confidentiality cannot be guaranteed on emails sent or received unencrypted