thunderbird build error NetBSD 9 i386

[Mike Pumford <mpumford%mudcovered.org.uk@localhost>]

Any idea how I can fix this:

/comp/obj/pkgsrc/mail/thunderbird/work/build/_virtualenvs/init_py3/bin/python 
-m mozbuild.action.file_generate 
/comp/obj/pkgsrc/mail/thunderbird/work/thunderbird-78.3.1/modules/libpref/init/generate_static_pref_list.py 
emit_code init/StaticPrefListAll.h init/.deps/StaticPrefListAll.h.pp 
init/.deps/StaticPrefListAll.h.stub 
/comp/obj/pkgsrc/mail/thunderbird/work/thunderbird-78.3.1/modules/libpref/init/StaticPrefList.yaml
gmake[3]: Entering directory 
'/comp/obj/pkgsrc/mail/thunderbird/work/build/netwerk/dns'
netwerk/dns/etld_data.inc.stub
/comp/obj/pkgsrc/mail/thunderbird/work/build/_virtualenvs/init_py3/bin/python 
-m mozbuild.action.file_generate 
/comp/obj/pkgsrc/mail/thunderbird/work/thunderbird-78.3.1/netwerk/dns/prepare_tlds.py 
main etld_data.inc .deps/etld_data.inc.pp .deps/etld_data.inc.stub 
/comp/obj/pkgsrc/mail/thunderbird/work/thunderbird-78.3.1/netwerk/dns/effective_tld_names.dat
(1, '   INFO: 
/comp/obj/pkgsrc/mail/thunderbird/work/thunderbird-78.3.1/comm/third_party/botan/configure.py 
invoked with options 
"--cc-bin=/comp/obj/pkgsrc/mail/thunderbird/work/.cwrapper/bin/c++ 
-std=gnu++11 --cpu=i486 --os=netbsd 
--with-build-dir=/comp/obj/pkgsrc/mail/thunderbird/work/build/comm/third_party/botan 
--minimized-build --disable-shared-library --link-method=copy 
--without-documentation --distribution-info=Thunderbird 78.3.1 rnp 
--with-cmake 
--enable-modules=aead,aes,auto_rng,bigint,blowfish,camellia,cast128,cbc,cfb,crc24,curve25519,des,dl_group,dsa,eax,ec_group,ecdh,ecdsa,ed25519,elgamal,eme_pkcs1,emsa_pkcs1,emsa_raw,ffi,hash,hmac,hmac_drbg,idea,kdf,md5,ocb,pgp_s2k,pubkey,rfc3394,rmd160,rsa,sha1,sha2_32,sha2_64,sha3,sm2,sm3,sm4,sp800_56a,system_rng,twofish"\n 
  INFO: Configuring to build Botan 2.15.0 (revision 
git:3ed6eaa3c1236aed844f5475e2df8b89b3286ac4)\n   INFO: Running under 
3.7.9 (default, Sep 29 2020, 20:45:31) [GCC 7.5.0]\n   INFO: Implicit 
--cxxflags=-O2 -D_FORTIFY_SOURCE=2 -I/usr/pkg/include -I/usr/include 
-I/usr/pkg/include/nspr -I/usr/pkg/include/nss/nss -I/usr/X11R7/include 
-I/usr/X11R7/include/libdrm -I/usr/pkg/include/glib-2.0 
-I/usr/pkg/include/gio-unix-2.0 -I/usr/pkg/lib/glib-2.0/include 
-I/usr/pkg/include/ffmpeg4 -I/usr/X11R7/include/freetype2 -march=i586 
-mstackrealign due to environment variable CXXFLAGS\n   INFO: Implicit 
--ldflags= -lpthread -Wl,-R/usr/pkg/lib/thunderbird -L/usr/pkg/lib 
-Wl,-R/usr/pkg/lib -L/usr/lib -Wl,-R/usr/lib -L/usr/pkg/lib/nspr 
-Wl,-R/usr/pkg/lib/nspr -L/usr/pkg/lib/nss -Wl,-R/usr/pkg/lib/nss 
-L/usr/X11R7/lib -Wl,-R/usr/X11R7/lib -L/usr/pkg/lib/ffmpeg4 
-Wl,-R/usr/pkg/lib/ffmpeg4 -Wl,-z,noexecstack -Wl,-z,text -Wl,-z,relro 
-Wl,-z,nocopyreloc -Wl,-Bsymbolic-functions -Wl,--build-id=sha1 
-fstack-protector-strong 
-Wl,-rpath-link,/comp/obj/pkgsrc/mail/thunderbird/work/build/dist/bin 
-Wl,-rpath-link,/usr/pkg/lib   due to environment variable LDFLAGS\n 
INFO: Autodetected platform information: OS="NetBSD" machine="i386" 
proc="i386"\n  ERROR: Unknown or unidentifiable processor "i486"\n', '')