Re: /lib/libc.so.7 vs. __libc_start1@FBSD_1.7 in main [so: 14] recently ?

From: Mark Millard <marklmi_at_yahoo.com>
Date: Mon, 24 Apr 2023 04:22:01 UTC
[Warner answered my specific question separately. This is about
something else.]

On Apr 23, 2023, at 20:57, Warner Losh <imp@bsdimp.com> wrote:

> On Sun, Apr 23, 2023 at 9:40 PM Simon J. Gerraty <sjg@juniper.net> wrote:
>> Mark Millard <marklmi@yahoo.com> wrote:
>> > I will not get into why, but I executed a git built for 1400082
>> > in a 1400081 world context and got what was to me a surprise,
>> > given that /lib/libc.so.7 is part of 13.2-RELEASE :
>> > 
>> > ld-elf.so.1: /usr/local/bin/git: Undefined symbol "__libc_start1@FBSD_1.7"
>> 
>> This is a symptom of trying to run a prog built for target on a host
>> which is not the same.
>> 
>> I hit this a lot recently while updating Makefile.depend files for
>> userland.
>> 
>> There are a number of makefiles (eg for sh, csh, awk) which need to run
>> a tool on the host to generate something.
>> When trying to build 14.0 on a 13.1 host each of those tools failed with
>> the above issue until actually built for the host.
> 
> Your path is messed up then. We always run (a copy of) the host's binaries
> for these tools.

For the kernel's vers.c generation, git is used but
does not get a build of its own under buildworld or
buildkernel as far as I know: not a bootstrap or
staged tool.

> If you were running the 14 binaries on 13 as part of the
> build process, the path is messed up. I'm not surprised for dirdep
> since it doesn't do all the staging activities that buildworld.

git use is not covered by buildworld or kernel-toolchain
staging activities as far as I know.

Is git the only example of such for things used by buildworld
or buildkernel ?

>> AFAIK the non-DIRDEPS_BUILD build does a separate pass through the tree
>> to do the target build-tools to build these things.
> 
> Yes and no... We copy the host's tools when we can, and build a matched set of
> binary and libraries when the host one isn't good enough. I think it's a path
> issue you are seeing...
> 
> Also, "copy" isn't a physical copy because macos hates copied binaries due to security concerns.
>  
>> 
>> The DIRDEPS_BUILD uses a pseudo MACHINE "host" to deal with such things,
>> ideally those tools would be built in a subdirectory of sh, csh etc, so
>> that one can choose to build only that tool if desired - sometimes you
>> want to build the app (eg awk) for the host as well but usually not.
> 
> Yea, buildworld deals with this by creating new binaries and installing them in
> a special directory, which is somewhat similar (though we always build
> them rather than on demand like dirdep hopes to do). 


===
Mark Millard
marklmi at yahoo.com