Thorsten Glaser: > Ximin Luo dixit: > >> needs to more clearly distinguish between the build and the host >> environment - like how compilers do. So for example, here the "most >> correct" solution would be to add a HOST_POSIX_SHELL and default this > > No, this is outside of the scope of autotools and a common misuse > of them actually. > > The real bug here is that the configure.ac script of the package > hardcodes POSIX_SHELL in the output while your reproducible builds > effort treats this as a(n unsupported, at least in this scenario) > cross compilation. > > The same issue would happen when you set CONFIG_SHELL=/bin/bash > and then cross-compile xz-utils from GNU/Linux to, say, MirBSD, > where There Is No Such Thing As /bin/bash. > > So the root of the problem is that xz-utils is not cross-compilable > (well, not completely, and enough for Helmut’s bootstrapping effort). >
I agree there is an issue with configure.ac, but it can only be fully solved via HOST_POSIX_SHELL. In other words, the reason that xz-utils is not completely cross-compilable is *because* there is no such thing as HOST_POSIX_SHELL. xz-utils (using gnulib macros) is *unable* to distinguish between these two cases: 1. build-time scripts that require a POSIX shell 2. places where it needs to embed POSIX_SHELL into a shebang line, for scripts installed into the host architecture xz-utils is forced to use POSIX_SHELL for both these cases, and that is where the "bug" comes in. It has nothing to do with reproducible builds, although it does manifest in a more obvious way if you are trying to reproducible a build across different machines. If HOST_POSIX_SHELL was available, then xz-utils could use this for case (2). Then, if we wanted to cross-compile xz-utils from GNU/Linux to MirBSD, we would set HOST_POSIX_SHELL to whatever shell works on MirBSD. Distinguishing cases (1) and (2) is not a "misuse" nor "outside the scope" of autotools, but a vital part of any well-engineered build tool. X -- GPG: ed25519/56034877E1F87C35 GPG: rsa4096/1318EFAC5FBBDBCE git://github.com/infinity0/pubkeys.git
