Hello Zack, many thanks for your helpful response! Zack Weinberg (2021/02/04 11:50 -0500): > Sorry for the blank reply, I misclicked. No problem. > > On Thu, Feb 4, 2021 at 11:27 AM Sébastien Hinderer <Sebastien.Hinderer@xxxxxxxx> wrote: > > > checking build system type... x86_64-pc-linux-gnu > > > checking host system type... aarch64-unknown-linux-gnu > > > checking target system type... aarch64-unknown-linux-gnu > > > > > > I am okay with the first line but to absolutely not understandthe second > > > and third line. Why do the host and system types contain an "unknown" > > > string? > > GNU canonical system identifiers are defined as 3- or 4-tuples: either > CPU-COMPANY-OS or CPU-COMPANY-KERNEL-LIBC. 'pc' and 'unknown' are > both filler words inserted in the COMPANY field when config.sub has > nothing more meaningful to put there. Yes, okay. > The COMPANY field was more useful many years ago, when lots of > different Unix vendors were putting out workstations based on the > MC68020 -- 'm68k-apollo-sysv' and 'm68k-bull-sysv' for instance are > distinguished only by COMPANY. Nowadays it's pretty much vestigial, > but we have to keep it around for compatibility with all the logic > that expects there to be at least three dash-separated fields in > $host_alias. So you agree that the --host=--host=aarch64-linux-gnu I used, although perhaps incorrect in its meaning, is syntactically correct, right? The thing is, the C cross-compiler for this OS type has this prefix, it's installed as aarch64-linux-gnu-gcc, so that's why I thought this was a correct system type. If I use the value returned by the canonicalizaiton, then I won't be able to find the tools byadding a - to the system type... > `aarch64-linux-gnu` is a *non-canonical* shorthand system identifier. Yeah, but still its the prefix of the tools I have, that was what confused me. > $host_alias is always set to the *canonical* system identifier, which > is computed from what you give as the argument to --host by passing it > through `config.sub`. I think you make a little mistake here. According to the docuemntation, it's host, rather than host_alias, which contains the canonicalized host system type. host_alias remains what you ahve given, empty if no argument to --host was given. As I understand it, host is used by ocnfigure, host_alias is for interacting with users. > You did not give a --target option, so $target_alias defaults to > $host_alias, No, target_alias is empty. It's the target environemnt varialbe wich defaults to host. > and both are in canonical form. No it's hsot and target which are in canonical form. > In summary, everything is working as intended. You do not need to > change how you are running configure. (You do, however, need to make > sure that any `case $host_alias in ... esac` blocks in your configure > script expect $host_alias to be in canonical form, e.g. `case > $host_alias in (aarch64-linux-gnu) ... ;; esac` will never execute the > ... code, it needs to be (aarch64-*-linux-gnu) instead.) The case should be on host, rather than on host_alias, I think. I'll fix my host type to make it correct and see whether the tools are still found. thanks, Sébastien.
