Re: musl vs. Debian policy

[Christian Neukirchen <chneukirchen@gmail.com>]

Rich Felker <dalias@aerifal.cx> writes:

> On Fri, Mar 08, 2013 at 04:13:59PM +0100, Christian Neukirchen wrote:
>> >> In this case, could we also change the SONAME of the library itself to
>> >> something not libc.so?  It would avoid this "bogus" warning of glibc
>> >> ldconfig...
>> >
>> > No, this is a lot more problematic and I see no benefits. For each
>> > possible SONAME musl may have been linked by, musl must contain a
>> > special-case to refuse to load this SONAME when it appears in
>> > DT_NEEDED. "libc.so" is a name that should never appear elsewhere. I
>> > don't want to keep expanding this list of names, and of course
>> > programs linked using a new SONAME would be gratuitously incompatible
>> > with an older musl ld.so that didn't have the new name included in its
>> > refuse-to-load list.
>> 
>> ld-musl-x86_64.so shouldn't appear elsewhere either.
>
> Yes and no. Formally, libc.so is in a sort of reserved namespace (or
> at least, -lc is), whereas there's nothing "reserved" about the name
> ld-musl-$(ARCH).so.1. I agree this is fairly irrelevant however as
> nobody else is going to use that library name unless they're trying to
> break things.
>
>> >> ldconfig: /usr/lib/libc.so is not a symbolic link
>> >
>> > IIRC this is happening due to some other misconfiguration. If nothing
>> > else, it means glibc and musl were both installed in /usr/lib, or
>> > ldconfig is configured for the wrong paths (since ldconfig has nothing
>> > to do with musl).
>> 
>> This happens because /lib/ld-musl-x86_64.so.1 has a SONAME of libc.so
>> (which should be the correct place).  The message is not harmful, but
>> annoying.
>
> Well the message should never happen unless ldconfig is processing the
> directory containing libc.so, right? It doesn't happen for me on
> Debian when I have musl's ld-musl-i386.so.1 in /lib and ldconfig
> processes the default library path.

That is weird...

stat("/usr/lib/libc.so", {st_mode=S_IFREG|0644, st_size=255, ...}) = 0
stat("/usr/lib/ld-musl-x86_64.so.1", {st_mode=S_IFREG|0755, st_size=583007, ...}) = 0
lstat("/usr/lib/libc.so", {st_mode=S_IFREG|0644, st_size=255, ...}) = 0
... glibc printf crap ...
write(2, "ldconfig: ", 10ldconfig: )              = 10
write(2, "/usr/lib/libc.so is not a symbol"..., 40/usr/lib/libc.so is not a symbolic link

Note that /usr/lib/libc.so is a glibc file containing an ld script here.

If I remove /usr/lib/ld-musl-x86_64.so.1, the message goes away.

But I think it also had something to do with 
lrwxrwxrwx   1 root root     7 Jan 27 08:29 lib -> usr/lib/

I thought the issue was that it found ld-musl-x86_64.so.1 and tried to
ensure libc.so points to it, due to the SONAME.

-- 
Christian Neukirchen  <chneukirchen@gmail.com>  http://chneukirchen.org