Comment 56 for bug 1710278

ok next challenge, named single-thread coredump as following:

# named -f -u bind
named: ../nptl/pthread_mutex_lock.c:79: __pthread_mutex_lock: Assertion `mutex->__data.__owner == 0' failed.
Aborted (core dumped)

Although named is clearly single threaded

# named -V
BIND <VERSION>-Ubuntu (Extended Support Version) <id:a375815>
running on Linux x86_64 5.0.0-20-generic #21-Ubuntu SMP Mon Jun 24 09:32:09 UTC 2019
built by make with '--build=x86_64-linux-gnu' '--prefix=/usr' '--includedir=/usr/include' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--sysconfdir=/etc' '--localstatedir=/var' '--disable-silent-rules' '--libdir=/usr/lib/x86_64-linux-gnu' '--libexecdir=/usr/lib/x86_64-linux-gnu' '--disable-maintainer-mode' '--disable-dependency-tracking' '--libdir=/usr/lib/x86_64-linux-gnu' '--sysconfdir=/etc/bind' '--with-python=python3' '--localstatedir=/' '--disable-threads' '--enable-largefile' '--with-libtool' '--enable-shared' '--enable-static' '--with-gost=no' '--with-openssl=/usr' '--with-gssapi=/usr' '--with-libjson=/usr' '--without-lmdb' '--with-gnu-ld' '--with-geoip=/usr' '--with-atf=no' '--enable-ipv6' '--enable-rrl' '--enable-filter-aaaa' '--disable-native-pkcs11' '--with-pkcs11=no' '--with-randomdev=/dev/urandom' '--with-eddsa=no' 'build_alias=x86_64-linux-gnu' 'CFLAGS=-g -O2 -fdebug-prefix-map=/build/bind9-MQj2Su/bind9-9.11.3+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security -fno-strict-aliasing -fno-delete-null-pointer-checks -DNO_VERSION_DATE -DDIG_SIGCHASE' 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now' 'CPPFLAGS=-Wdate-time -D_FORTIFY_SOURCE=2'
compiled by GCC 7.4.0
compiled with OpenSSL version: OpenSSL 1.1.1 11 Sep 2018
linked to OpenSSL version: OpenSSL 1.1.1 11 Sep 2018
compiled with libxml2 version: 2.9.4
linked to libxml2 version: 20904
compiled with libjson-c version: 0.12.1
linked to libjson-c version: 0.12.1
compiled with zlib version: 1.2.11
linked to zlib version: 1.2.11
threads support is disabled

I'll build/publish the debug symbol and see what is missing (possibly libs built by the bind9 source need to be single-threaded too)