Re: [PATCH] erofs-utils: build: link tools with liberofs dependencies

On 2026/6/3 22:36, Gao Xiang wrote:
> Hi Yifan,
>
> On Fri, May 29, 2026 at 03:17:02PM +0800, Yifan Zhao wrote:
>> liberofs.la is a noinst libtool archive, so relying on its
>> dependency_libs to carry external libraries is not enough for
>> static-only dependencies.
>>
>> For example, when liblzma is installed as a static libtool archive,
>> libtool consumes -llzma while creating liberofs.la but does not record it
>> in dependency_libs.  The final tools then link only with liberofs.la and
>> fail with undefined lzma_* references.
>>
>> Collect liberofs external libraries in LIBEROFS_LIBS and use it for both
>> liberofs.la and the final tools, so final executable links see the
>> pkg-config supplied liblzma flags directly.
>>
>> Reported-by: Guo Xuenan <[email protected]>
>> Fixes: 6c2a000782b2 ("erofs-utils: lib: add test for s3erofs_prepare_url()")
>> Assisted-by: Codex:GPT-5.5
>> Signed-off-by: Yifan Zhao <[email protected]>
>> ---
>> To reproduce link error:
>>
>>      ./autogen.sh
>>      PKG_CONFIG_PATH=/path/to/xz-static/lib/pkgconfig ./configure
>>      make -j
>>
>> Then {mkfs,dump,fsck}.erofs reports missing lzma_* symbol as `-llzma`
>> missing in ld flags.
>>
>>   configure.ac      | 17 +++++++++++++++++
>>   dump/Makefile.am  |  2 +-
>>   fsck/Makefile.am  |  4 ++--
>>   fuse/Makefile.am  |  5 +++--
>>   lib/Makefile.am   | 14 +++-----------
>>   mkfs/Makefile.am  |  2 +-
>>   mount/Makefile.am |  2 +-
>>   7 files changed, 28 insertions(+), 18 deletions(-)
>>
>> diff --git a/configure.ac b/configure.ac
>> index f68bb74..17b4856 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -790,6 +790,23 @@ AM_CONDITIONAL([ENABLE_STATIC_FUSE], [test "x${enable_static_fuse}" = "xyes"])
>>   AM_CONDITIONAL([ENABLE_OCI], [test "x${have_oci}" = "xyes"])
>>   AM_CONDITIONAL([ENABLE_FANOTIFY], [test "x${have_fanotify}" = "xyes"])
>>   
>> +LIBEROFS_LIBS="${libselinux_LIBS} ${libuuid_LIBS} ${liblz4_LIBS} \
>> +${liblzma_LIBS} ${zlib_LIBS} ${libdeflate_LIBS} ${libzstd_LIBS} \
>> +${libqpl_LIBS} ${libcurl_LIBS} ${openssl_LIBS} ${json_c_LIBS}"
>> +AS_IF([test "x${have_xxhash}" = "xyes"], [
>> +  LIBEROFS_LIBS="${LIBEROFS_LIBS} ${libxxhash_LIBS}"
>> +])
>> +AS_IF([test "x${have_s3}" = "xyes"], [
>> +  LIBEROFS_LIBS="${LIBEROFS_LIBS} ${libxml2_LIBS}"
>> +])
>> +AS_IF([test "x${enable_multithreading}" != "xno"], [
>> +  LIBEROFS_LIBS="${LIBEROFS_LIBS} -lpthread"
>> +])
>> +AS_IF([test "x${build_linux}" = "xyes"], [
>> +  LIBEROFS_LIBS="${LIBEROFS_LIBS} ${libnl3_LIBS}"
>> +])
> Although I admit that I'm not super happy with this approach, but it
> seems that we have to do like this.
>
> My only question here is that why  ${libxxhash_LIBS},  ${libxml2_LIBS}
> and ${libnl3_LIBS} cannot be appended directly to LIBEROFS_LIBS as
> others.

As these flags were conditionally appended to liberofs_la_LDFLAGS in the 
original lib/Makefile.am code path.


Thanks,

Yifan

> But I think it's fine to guard `-lpthread` with enable_multithreading
> tho.
>
> Thanks,
> Gao Xiang
>