On Sat, May 28, 2016 at 4:04 PM, Johannes Schauer wrote: > Having such a reliable tracing method would give us the ability to reliably > infer copyright information as well as generating structured build logs > (knowing for each line in the build log the process (tree) that created it). > > Both of these would also tremendously help debugging problems. For example, > for > fixing reproducible build problems, I was often puzzled which program actually > created a file that I was interested in for a source package that I am not > familiar with.
Thanks for these other use-cases, very interesting. > Unfortunately though, there seems to be no way to reliably trace process > execution and read/write/open/close system calls without either sometimes > missing information or breaking builds... I expect this would need some support from the kernel being run under. OTOH I don't think a tracing mechanism is what is needed though, since the kernel cannot know what the program is doing with each file being read/written by the program. These sort of semantics (input, output and code) are only known by the program that is doing the transformations. Especially when you factor in shell scripts and other things, the semantics get complicated. Kernel support would definitely be useful though. Perhaps we could have a brainstorm/BoF about this at a DebConf some time. -- bye, pabs https://wiki.debian.org/PaulWise
