On April 3, 2018 7:25:03 PM GMT+01:00, Sune Vuorela <s...@debian.org> wrote: >On Saturday, March 31, 2018 12:05:02 PM CEST Chris Lamb wrote: >> > While investigating ultracopier's lack of build reproducibility, I >found >> > out that rcc encodes the timestamp of the files the QRC file being >> > compiled references > >I don't actually see why this should be a problem. If input changes, >output >changes. >I do think that using touch(1) on the input should allow different >output. > >It is quite easy to reproduce: > >qtbase/tests/auto/gui/image/qimage/foo (dev $%=)$ rcc --format-version >2 ../ >qimage.qrc -o 1 >qtbase/tests/auto/gui/image/qimage/foo (dev $%=)$ rcc --format-version >2 ../ >qimage.qrc -o 2 >qtbase/tests/auto/gui/image/qimage/foo (dev $%=)$ rcc --format-version >2 ../ >qimage.qrc -o 3 > >Gives same output. >Even adding in touch ../qimage.qrc keeps the same output. > >qtbase/tests/auto/gui/image/qimage/foo (dev $%=)$ rcc --format-version >2 ../ >qimage.qrc -o 4 > >touch ../images/image.bmp > >qtbase/tests/auto/gui/image/qimage/foo (dev $%=)$ rcc --format-version >2 ../ >qimage.qrc -o 5 > >is needed to get different output > >14ef6dae8e4992ce907948c1c4af272b 1 >14ef6dae8e4992ce907948c1c4af272b 2 >14ef6dae8e4992ce907948c1c4af272b 3 >14ef6dae8e4992ce907948c1c4af272b 4 >54c6f8c09a347955ae2f36e68bbd2539 5 > > >So. What touches the files? > >/Sune >-- >I didn’t stop pretending when I became an adult, it’s just that when I >was a >kid I was pretending that I fit into the rules and structures of this >world. >And now that I’m an adult, I pretend that those rules and structures >exist. > - zefrank
Hi Sune, The problematic files are Qt message files (ie .qm files) generated at build time via lrelease from translation files (ie .ts files). Therefore two different builds will generate those .qm files at different times which will end up with different cpp files generated by rcc. Currently I'm working around it by setting the modified time of those .qm files to EPOCH after they are generated. I think it would be nice if there was a way for rcc to avoid doing that manually. I agree with Chris that honouring SOURCE_DATE_EPOCH in rcc would be a nice solution. Best regards, Thomas
