Build of libidn2 failed with duplicate symbols. Full build logs of failed and working builds, and config.log from failed build, attached.
libtool: link: cc -shared -fPIC -DPIC -o .libs/libidn2.so.1.1 -fno-common -W -Wabsolute-value -Waddress -Waddress-of-packed-member -Wall -Wattributes -Wbad-function-cast -Wbuiltin-macro-redefined -Wcast-align -Wchar-subscripts -Wcomment -Wcomments -Wcpp -Wdangling-else -Wdate-time -Wdeprecated -Wdeprecated-declarations -Wdisabled-optimization -Wdiv-by-zero -Wdouble-promotion -Wduplicate-decl-specifier -Wempty-body -Wendif-labels -Wenum-compare -Wexpansion-to-defined -Wextra -Wformat-extra-args -Wformat-nonliteral -Wformat-security -Wformat-y2k -Wformat-zero-length -Wignored-attributes -Wignored-qualifiers -Wimplicit -Wimplicit-function-declaration -Wimplicit-int -Wincompatible-pointer-types -Winit-self -Winline -Wint-conversion -Wint-to-pointer-cast -Winvalid-pch -Wlogical-not-parentheses -Wmain -Wmemset-transposed-args -Wmissing-braces -Wmissing-declarations -Wmissing-include-dirs -Wmissing-prototypes -Wmultichar -Wnarrowing -Wnested-externs -Wnonnull -Wnull-dereference -Wodr -Wold-style-definition -Woverflow -Woverlength-strings -Woverride-init -Wpacked -Wparentheses -Wpointer-arith -Wpointer-sign -Wpointer-to-int-cast -Wpragmas -Wreturn-type -Wsequence-point -Wshadow -Wshift-count-negative -Wshift-count-overflow -Wshift-negative-value -Wsizeof-array-argument -Wsizeof-pointer-div -Wsizeof-pointer-memaccess -Wstack-protector -Wstrict-aliasing -Wstrict-overflow -Wstrict-prototypes -Wswitch -Wswitch-bool -Wtautological-compare -Wtrigraphs -Wtype-limits -Wuninitialized -Wunknown-pragmas -Wunused -Wunused-function -Wunused-label -Wunused-local-typedefs -Wunused-parameter -Wunused-result -Wunused-value -Wunused-variable -Wvarargs -Wvariadic-macros -Wvla -Wvolatile-register-var -Wwrite-strings -fdiagnostics-show-option -Wno-missing-field-initializers -fvisibility=hidden -O2 -pipe -Wl,--version-script=./idn2.map .libs/idna.o .libs/lookup.o .libs/decode.o .libs/register.o .libs/bidi.o .libs/version.o .libs/error.o .libs/puny_encode.o .libs/puny_decode.o .libs/free.o .libs/data.o .libs/tr46map.o .libs/tables.o .libs/context.o -Wl,-whole-archive /pobj/libidn2-2.3.0/libidn2-2.3.0/gl/.libs/libgnu.a /pobj/libidn2-2.3.0/libidn2-2.3.0/unistring/.libs/libunistring.a /pobj/libidn2-2.3.0/libidn2-2.3.0/unistring/.libs/libunistring.a -Wl,-no-whole-archive -L.libs -liconv -lunistring -Wl,-soname,libidn2.so.1.1 ld: error: duplicate symbol: c_isalnum >>> defined at c-ctype.c >>> c-ctype.o:(c_isalnum) in archive >>> /pobj/libidn2-2.3.0/libidn2-2.3.0/unistring/.libs/libunistring.a >>> defined at c-ctype.c >>> c-ctype.o:(.text+0x0) in archive >>> /pobj/libidn2-2.3.0/libidn2-2.3.0/unistring/.libs/libunistring.a (etc. for various ctypes symbols).
libidn2.failed.gz
Description: application/gunzip
libidn2.ok.gz
Description: application/gunzip
config.log.gz
Description: application/gunzip
