On Tue, Dec 05 2017, Junio C. Hamano jotted: > Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> writes: > >>> I'm not sure how I feel about this. I see your point that there's no >>> real value in maintaining two systems indefinitely. At the same time, I >>> wonder how much value the submodule strategy is actually bringing us. >>> >>> IOW, are we agreed that the path forward is to get everybody using the >>> submodule? >> ... >> In no particular order: >> >> * I don't feel strongly about 2-4/4 in this series. I just hacked this >> up because it occurred to me that I'd left this sha1dc stuff in some >> in-between state and we'd talked about eventually moving forward with >> this. > > Good. > >> We've had two releases with the submodule being purely optional, if >> we're going to keep it it seems logical to start at least using it by >> default. > > With a need for a patch like 1/4, I suspect two release cycles is > way too short for making a move like 2-4/4, though. You're conflating two unrelated things, which to be fair I'm confusingly doing by submitting all this together. 1) Since 2.14 we've had the "auto" rule and DC_SHA1_SUBMODULE=[YesPlease|auto], so we'll prefer the submodule if it's there. So we've been testing if the mere presence of a .gitmodules breaks something for someone, seems like it doesn't. 2) Then in the 2.15 release Takashi Iwai submitted a feature to link to an external SHA1DC. This is used in the SuSE 2.15 package here: http://download.opensuse.org/tumbleweed/repo/src-oss/suse/src/ However, as you'll see if you extract that package they don't run into that bug, because they're building it from a tarball which has an empty sha1collisiondetection/ directory as noted in my 87bmjdscdr.fsf@xxxxxxxxxxxxxxxxxxxxx. Takashi *would* run into an error with my 1/4 if he was building from git.git, or if "make dist" included sha1collisiondetection/, but I don't see a reason to hold anything back back on that account. The only users of DC_SHA1_EXTERNAL=YesPlease are going to be packagers who know what they're doing, and if we start erroring out for them on this obscure option that's going to be trivially solved. I don't see why this obscure edge case with #2 should keep us from deciding whatever we'd decide with #1. They're really unrelated, #2 practically speaking only impacts tarball consumers, #1 impacts git.git users. It seems logical to me if we're going to move forward with #1 at all by first making the submodule the default & then depending on how that turns out making it a hard dependency, we'd do it now. We'll learn nothing new by shipping a 2.16 with DC_SHA1_SUBMODULE=auto that we haven't already learned in 2.14 & 2.15.
