Comment # 1 on bug 1182252 from Martin Li������ka

So it's related to icu package where libicuuc.so.67 is built:

$ g++ -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector-strong -funwind-tables
-fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type
-flto=auto -g -DICU_DATA_DIR=\"/usr/share/icu/67.1/\" -W -Wall -pedantic
-Wpointer-arith -Wwrite-strings -Wno-long-long -std=c++11    -flto=auto  
-shared -Wl,-Bsymbolic -Wl,-soname -Wl,libicuuc.so.67 -o
../lib/libicuuc.so.67.1 errorcode.o putil.o umath.o utypes.o uinvchar.o
umutex.o ucln_cmn.o uinit.o uobject.o cmemory.o charstr.o cstr.o udata.o
ucmndata.o udatamem.o umapfile.o udataswp.o utrie_swap.o ucol_swp.o utrace.o
uhash.o uhash_us.o uenum.o ustrenum.o uvector.o ustack.o uvectr32.o uvectr64.o
ucnv.o ucnv_bld.o ucnv_cnv.o ucnv_io.o ucnv_cb.o ucnv_err.o ucnvlat1.o
ucnv_u7.o ucnv_u8.o ucnv_u16.o ucnv_u32.o ucnvscsu.o ucnvbocu.o ucnv_ext.o
ucnvmbcs.o ucnv2022.o ucnvhz.o ucnv_lmb.o ucnvisci.o ucnvdisp.o ucnv_set.o
ucnv_ct.o resource.o uresbund.o ures_cnv.o uresdata.o resbund.o resbund_cnv.o
ucurr.o localebuilder.o localeprioritylist.o messagepattern.o ucat.o locmap.o
uloc.o locid.o locutil.o locavailable.o locdispnames.o locdspnm.o loclikely.o
locresdata.o lsr.o loclikelysubtags.o locdistance.o localematcher.o
bytestream.o stringpiece.o bytesinkutil.o stringtriebuilder.o
bytestriebuilder.o bytestrie.o bytestrieiterator.o ucharstrie.o
ucharstriebuilder.o ucharstrieiterator.o dictionarydata.o edits.o appendable.o
ustr_cnv.o unistr_cnv.o unistr.o unistr_case.o unistr_props.o utf_impl.o
ustring.o ustrcase.o ucasemap.o ucasemap_titlecase_brkiter.o cstring.o
ustrfmt.o ustrtrns.o ustr_wcs.o utext.o unistr_case_locale.o ustrcase_locale.o
unistr_titlecase_brkiter.o ustr_titlecase_brkiter.o normalizer2impl.o
normalizer2.o filterednormalizer2.o normlzr.o unorm.o unormcmp.o
loadednormalizer2impl.o chariter.o schriter.o uchriter.o uiter.o patternprops.o
uchar.o uprops.o ucase.o propname.o ubidi_props.o characterproperties.o ubidi.o
ubidiwrt.o ubidiln.o ushape.o uscript.o uscript_props.o usc_impl.o unames.o
utrie.o utrie2.o utrie2_builder.o ucptrie.o umutablecptrie.o bmpset.o
unisetspan.o uset_props.o uniset_props.o uniset_closure.o uset.o uniset.o
usetiter.o ruleiter.o caniter.o unifilt.o unifunct.o uarrsort.o brkiter.o
ubrk.o brkeng.o dictbe.o filteredbrk.o rbbi.o rbbidata.o rbbinode.o rbbirb.o
rbbiscan.o rbbisetb.o rbbistbl.o rbbitblb.o rbbi_cache.o serv.o servnotf.o
servls.o servlk.o servlkf.o servrbf.o servslkf.o uidna.o usprep.o uts46.o
punycode.o util.o util_props.o parsepos.o locbased.o cwchar.o wintz.o dtintrv.o
ucnvsel.o propsvec.o ulist.o uloc_tag.o icudataver.o icuplug.o sharedobject.o
simpleformatter.o unifiedcache.o uloc_keytype.o ubiditransform.o pluralmap.o
static_unicode_sets.o restrace.o -L../lib -L../stubdata -licudata -lpthread
-ldl -lm 

what makes a difference is that:
$ readelf  -d ../lib/libicuuc.so.67.1           

Dynamic section at offset 0x1e6cc0 contains 34 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libicudata.so.67]
 0x0000000000000001 (NEEDED)             Shared library: [libdl.so.2]
 0x0000000000000001 (NEEDED)             Shared library: [libstdc++.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libgcc_s.so.1]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [ld-linux-x86-64.so.2]

while the same library from my TW looks like:

readelf -d /usr/lib64/libicuuc.so.67.1

Dynamic section at offset 0x1e6ca0 contains 35 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libicudata.so.67]
 0x0000000000000001 (NEEDED)             Shared library: [libpthread.so.0]
 0x0000000000000001 (NEEDED)             Shared library: [libdl.so.2]
 0x0000000000000001 (NEEDED)             Shared library: [libstdc++.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libgcc_s.so.1]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [ld-linux-x86-64.so.2]
 0x000000000000000e (SONAME)             Library soname: [libicuuc.so.67]

So we miss for some reason dependency on libpthread.so.0. Note that "-lpthread"
is present at the command line.
@Michael, Richard: Can one --as-needed automagic happen here?