https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104117
--- Comment #12 from Sergey Fedorov <vital.had at gmail dot com> --- Not sure if the error is related, but trying to build icu with gcc6 in Macports gives this: /opt/local/bin/g++-mp-6 -DU_ATTRIBUTE_DEPRECATED= -DU_I18N_IMPLEMENTATION -DU_HAVE_STRTOD_L=1 -DU_HAVE_XLOCALE_H=1 -I. -I../common -pipe -Os -m32 -D_GLIBCXX_USE_CXX11_ABI=0 -W -Wall -pedantic -Wpointer-arith -Wwrite-strings -Wno-long-long -std=c++11 -fvisibility=hidden -fno-common -c -dynamic -MMD -MT "formatted_string_builder.d formatted_string_builder.o formatted_string_builder.ao" -o formatted_string_builder.o formatted_string_builder.cpp ar r -c ../lib/libicui18n.a ucln_in.ao fmtable.ao format.ao msgfmt.ao umsg.ao numfmt.ao unum.ao decimfmt.ao dcfmtsym.ao fmtable_cnv.ao choicfmt.ao datefmt.ao smpdtfmt.ao reldtfmt.ao dtfmtsym.ao udat.ao dtptngen.ao udatpg.ao nfrs.ao nfrule.ao nfsubs.ao rbnf.ao numsys.ao unumsys.ao ucsdet.ao ucal.ao calendar.ao gregocal.ao timezone.ao simpletz.ao olsontz.ao astro.ao taiwncal.ao buddhcal.ao persncal.ao islamcal.ao japancal.ao gregoimp.ao hebrwcal.ao indiancal.ao chnsecal.ao cecal.ao coptccal.ao dangical.ao ethpccal.ao coleitr.ao coll.ao sortkey.ao bocsu.ao ucoleitr.ao ucol.ao ucol_res.ao ucol_sit.ao collation.ao collationsettings.ao collationdata.ao collationtailoring.ao collationdatareader.ao collationdatawriter.ao collationfcd.ao collationiterator.ao utf16collationiterator.ao utf8collationiterator.ao uitercollationiterator.ao collationsets.ao collationcompare.ao collationfastlatin.ao collationkeys.ao rulebasedcollator.ao collationroot.ao collationrootelements.ao collationdatabuilder.ao collationweights.ao collationruleparser.ao collationbuilder.ao collationfastlatinbuilder.ao listformatter.ao ulistformatter.ao strmatch.ao usearch.ao search.ao stsearch.ao translit.ao utrans.ao esctrn.ao unesctrn.ao funcrepl.ao strrepl.ao tridpars.ao cpdtrans.ao rbt.ao rbt_data.ao rbt_pars.ao rbt_rule.ao rbt_set.ao nultrans.ao remtrans.ao casetrn.ao titletrn.ao tolowtrn.ao toupptrn.ao anytrans.ao name2uni.ao uni2name.ao nortrans.ao quant.ao transreg.ao brktrans.ao regexcmp.ao rematch.ao repattrn.ao regexst.ao regextxt.ao regeximp.ao uregex.ao uregexc.ao ulocdata.ao measfmt.ao currfmt.ao curramt.ao currunit.ao measure.ao utmscale.ao csdetect.ao csmatch.ao csr2022.ao csrecog.ao csrmbcs.ao csrsbcs.ao csrucode.ao csrutf8.ao inputext.ao wintzimpl.ao windtfmt.ao winnmfmt.ao basictz.ao dtrule.ao rbtz.ao tzrule.ao tztrans.ao vtzone.ao zonemeta.ao standardplural.ao upluralrules.ao plurrule.ao plurfmt.ao selfmt.ao dtitvfmt.ao dtitvinf.ao udateintervalformat.ao tmunit.ao tmutamt.ao tmutfmt.ao currpinf.ao uspoof.ao uspoof_impl.ao uspoof_build.ao uspoof_conf.ao smpdtfst.ao ztrans.ao zrule.ao vzone.ao fphdlimp.ao fpositer.ao ufieldpositer.ao decNumber.ao decContext.ao alphaindex.ao tznames.ao tznames_impl.ao tzgnames.ao tzfmt.ao compactdecimalformat.ao gender.ao region.ao scriptset.ao uregion.ao reldatefmt.ao quantityformatter.ao measunit.ao measunit_extra.ao sharedbreakiterator.ao scientificnumberformatter.ao dayperiodrules.ao nounit.ao number_affixutils.ao number_compact.ao number_decimalquantity.ao number_decimfmtprops.ao number_fluent.ao number_formatimpl.ao number_grouping.ao number_integerwidth.ao number_longnames.ao number_modifiers.ao number_notation.ao number_output.ao number_padding.ao number_patternmodifier.ao number_patternstring.ao number_rounding.ao number_scientific.ao number_utils.ao number_asformat.ao number_mapper.ao number_multiplier.ao number_currencysymbols.ao number_skeletons.ao number_capi.ao double-conversion-string-to-double.ao double-conversion-double-to-string.ao double-conversion-bignum-dtoa.ao double-conversion-bignum.ao double-conversion-cached-powers.ao double-conversion-fast-dtoa.ao double-conversion-strtod.ao string_segment.ao numparse_parsednumber.ao numparse_impl.ao numparse_symbols.ao numparse_decimal.ao numparse_scientific.ao numparse_currency.ao numparse_affixes.ao numparse_compositions.ao numparse_validators.ao numrange_fluent.ao numrange_impl.ao erarules.ao formattedvalue.ao formattedval_iterimpl.ao formattedval_sbimpl.ao formatted_string_builder.ao /opt/local/bin/ranlib: file: ../lib/libicui18n.a(wintzimpl.ao) has no symbols /opt/local/bin/ranlib: file: ../lib/libicui18n.a(windtfmt.ao) has no symbols /opt/local/bin/ranlib: file: ../lib/libicui18n.a(winnmfmt.ao) has no symbols ranlib ../lib/libicui18n.a ranlib: file: ../lib/libicui18n.a(wintzimpl.ao) has no symbols ranlib: file: ../lib/libicui18n.a(windtfmt.ao) has no symbols ranlib: file: ../lib/libicui18n.a(winnmfmt.ao) has no symbols /opt/local/bin/g++-mp-6 -dynamiclib -dynamic -pipe -Os -m32 -D_GLIBCXX_USE_CXX11_ABI=0 -W -Wall -pedantic -Wpointer-arith -Wwrite-strings -Wno-long-long -std=c++11 -fvisibility=hidden -Wl,-headerpad_max_install_names -Wl,-read_only_relocs,suppress -m32 -Wl,-compatibility_version -Wl,67 -Wl,-current_version -Wl,67.1 -install_name /opt/local/lib/libicui18n.67.dylib -o ../lib/libicui18n.67.1.dylib ucln_in.o fmtable.o format.o msgfmt.o umsg.o numfmt.o unum.o decimfmt.o dcfmtsym.o fmtable_cnv.o choicfmt.o datefmt.o smpdtfmt.o reldtfmt.o dtfmtsym.o udat.o dtptngen.o udatpg.o nfrs.o nfrule.o nfsubs.o rbnf.o numsys.o unumsys.o ucsdet.o ucal.o calendar.o gregocal.o timezone.o simpletz.o olsontz.o astro.o taiwncal.o buddhcal.o persncal.o islamcal.o japancal.o gregoimp.o hebrwcal.o indiancal.o chnsecal.o cecal.o coptccal.o dangical.o ethpccal.o coleitr.o coll.o sortkey.o bocsu.o ucoleitr.o ucol.o ucol_res.o ucol_sit.o collation.o collationsettings.o collationdata.o collationtailoring.o collationdatareader.o collationdatawriter.o collationfcd.o collationiterator.o utf16collationiterator.o utf8collationiterator.o uitercollationiterator.o collationsets.o collationcompare.o collationfastlatin.o collationkeys.o rulebasedcollator.o collationroot.o collationrootelements.o collationdatabuilder.o collationweights.o collationruleparser.o collationbuilder.o collationfastlatinbuilder.o listformatter.o ulistformatter.o strmatch.o usearch.o search.o stsearch.o translit.o utrans.o esctrn.o unesctrn.o funcrepl.o strrepl.o tridpars.o cpdtrans.o rbt.o rbt_data.o rbt_pars.o rbt_rule.o rbt_set.o nultrans.o remtrans.o casetrn.o titletrn.o tolowtrn.o toupptrn.o anytrans.o name2uni.o uni2name.o nortrans.o quant.o transreg.o brktrans.o regexcmp.o rematch.o repattrn.o regexst.o regextxt.o regeximp.o uregex.o uregexc.o ulocdata.o measfmt.o currfmt.o curramt.o currunit.o measure.o utmscale.o csdetect.o csmatch.o csr2022.o csrecog.o csrmbcs.o csrsbcs.o csrucode.o csrutf8.o inputext.o wintzimpl.o windtfmt.o winnmfmt.o basictz.o dtrule.o rbtz.o tzrule.o tztrans.o vtzone.o zonemeta.o standardplural.o upluralrules.o plurrule.o plurfmt.o selfmt.o dtitvfmt.o dtitvinf.o udateintervalformat.o tmunit.o tmutamt.o tmutfmt.o currpinf.o uspoof.o uspoof_impl.o uspoof_build.o uspoof_conf.o smpdtfst.o ztrans.o zrule.o vzone.o fphdlimp.o fpositer.o ufieldpositer.o decNumber.o decContext.o alphaindex.o tznames.o tznames_impl.o tzgnames.o tzfmt.o compactdecimalformat.o gender.o region.o scriptset.o uregion.o reldatefmt.o quantityformatter.o measunit.o measunit_extra.o sharedbreakiterator.o scientificnumberformatter.o dayperiodrules.o nounit.o number_affixutils.o number_compact.o number_decimalquantity.o number_decimfmtprops.o number_fluent.o number_formatimpl.o number_grouping.o number_integerwidth.o number_longnames.o number_modifiers.o number_notation.o number_output.o number_padding.o number_patternmodifier.o number_patternstring.o number_rounding.o number_scientific.o number_utils.o number_asformat.o number_mapper.o number_multiplier.o number_currencysymbols.o number_skeletons.o number_capi.o double-conversion-string-to-double.o double-conversion-double-to-string.o double-conversion-bignum-dtoa.o double-conversion-bignum.o double-conversion-cached-powers.o double-conversion-fast-dtoa.o double-conversion-strtod.o string_segment.o numparse_parsednumber.o numparse_impl.o numparse_symbols.o numparse_decimal.o numparse_scientific.o numparse_currency.o numparse_affixes.o numparse_compositions.o numparse_validators.o numrange_fluent.o numrange_impl.o erarules.o formattedvalue.o formattedval_iterimpl.o formattedval_sbimpl.o formatted_string_builder.o -L../lib -licuuc -L../stubdata -licudata -lpthread -lm ld: duplicate symbol icu_67::number::NumberFormatterSettings<icu_67::number::UnlocalizedNumberFormatter>::copyErrorTo(UErrorCode&) const in number_skeletons.o and number_fluent.o collect2: error: ld returned 1 exit status gnumake[1]: *** [../lib/libicui18n.67.1.dylib] Error 1 gnumake[1]: Leaving directory `/opt/local/var/macports/build/_opt_PPCLeopardPorts_devel_icu/icu/work/icu/source-ppc/i18n' gnumake: *** [all-recursive] Error 2 gnumake: Leaving directory `/opt/local/var/macports/build/_opt_PPCLeopardPorts_devel_icu/icu/work/icu/source-ppc' Command failed: cd "/opt/local/var/macports/build/_opt_PPCLeopardPorts_devel_icu/icu/work/icu/source-ppc" && /usr/bin/gnumake -j4 -w all VERBOSE=1 Exit code: 2 Error: Failed to build icu: command execution failed