Build error with Varnish 6.6.2-1

[jgarrouste]

Hi,

The build failed using Varnish 6.6.2-1.

I used the Varnish Ubuntu (focal) package from https://packagecloud.io/varnishcache/varnish66/

# dpkg -l | grep varnish
ii  varnish                      6.6.2-1~focal                           amd64        state of the art, high-performance web accelerator
ii  varnish-dev                  6.6.2-1~focal                           amd64        development files for Varnish Cache

# git clone https://github.com/ip2location/IP2Location-Varnish.git
# cd IP2Location-Varnish/
# ./autogen.sh && ./configure && make
[...]
make  all-recursive
make[1]: Entering directory '/root/IP2Location-Varnish'
Making all in src
make[2]: Entering directory '/root/IP2Location-Varnish/src'
/usr/share/varnish/vmodtool.py ../src/vmod_ip2location.vcc
/bin/bash ../libtool  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. -I..  -I/usr/include/varnish  -Wall -Wextra -Werror -g -O2 -MT vcc_if.lo -MD -MP -MF .deps/vcc_if.Tpo -c -o vcc_if.lo vcc_if.c
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -I/usr/include/varnish -Wall -Wextra -Werror -g -O2 -MT vcc_if.lo -MD -MP -MF .deps/vcc_if.Tpo -c vcc_if.c  -fPIC -DPIC -o .libs/vcc_if.o
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -I/usr/include/varnish -Wall -Wextra -Werror -g -O2 -MT vcc_if.lo -MD -MP -MF .deps/vcc_if.Tpo -c vcc_if.c -o vcc_if.o >/dev/null 2>&1
mv -f .deps/vcc_if.Tpo .deps/vcc_if.Plo
/bin/bash ../libtool  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. -I..  -I/usr/include/varnish  -Wall -Wextra -Werror -g -O2 -MT vmod_ip2location.lo -MD -MP -MF .deps/vmod_ip2location.Tpo -c -o vmod_ip2location.lo vmod_ip2location.c
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -I/usr/include/varnish -Wall -Wextra -Werror -g -O2 -MT vmod_ip2location.lo -MD -MP -MF .deps/vmod_ip2location.Tpo -c vmod_ip2location.c  -fPIC -DPIC -o .libs/vmod_ip2location.o
vmod_ip2location.c: In function 'convert':
vmod_ip2location.c:79:9: error: ignoring return value of 'gcvt' declared with attribute 'warn_unused_result' [-Werror=unused-result]
   79 |         gcvt(f, 5, buf);
      |         ^~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[2]: *** [Makefile:456: vmod_ip2location.lo] Error 1
make[2]: Leaving directory '/root/IP2Location-Varnish/src'
make[1]: *** [Makefile:516: all-recursive] Error 1
make[1]: Leaving directory '/root/IP2Location-Varnish'
make: *** [Makefile:384: all] Error 2

Temporary Solution :

# CFLAGS=-Wno-error ./configure && make
[...]
make  all-recursive
make[1]: Entering directory '/root/IP2Location-Varnish'
Making all in src
make[2]: Entering directory '/root/IP2Location-Varnish/src'
/bin/bash ../libtool  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. -I..  -I/usr/include/varnish  -Wall -Wextra -Werror -Wno-error -MT vmod_ip2location.lo -MD -MP -MF .deps/vmod_ip2location.Tpo -c -o vmod_ip2location.lo vmod_ip2location.c
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -I/usr/include/varnish -Wall -Wextra -Werror -Wno-error -MT vmod_ip2location.lo -MD -MP -MF .deps/vmod_ip2location.Tpo -c vmod_ip2location.c  -fPIC -DPIC -o .libs/vmod_ip2location.o
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -I/usr/include/varnish -Wall -Wextra -Werror -Wno-error -MT vmod_ip2location.lo -MD -MP -MF .deps/vmod_ip2location.Tpo -c vmod_ip2location.c -o vmod_ip2location.o >/dev/null 2>&1
mv -f .deps/vmod_ip2location.Tpo .deps/vmod_ip2location.Plo
/bin/bash ../libtool  --tag=CC   --mode=link gcc -Wall -Wextra -Werror -Wno-error -module -export-dynamic -avoid-version -shared -lIP2Location  -o libvmod_ip2location.la -rpath /usr/lib/varnish/vmods vcc_if.lo vmod_ip2location.lo  
libtool: link: gcc -shared  -fPIC -DPIC  .libs/vcc_if.o .libs/vmod_ip2location.o   /usr/lib/x86_64-linux-gnu/libIP2Location.so    -Wl,-soname -Wl,libvmod_ip2location.so -o .libs/libvmod_ip2location.so
libtool: link: ( cd ".libs" && rm -f "libvmod_ip2location.la" && ln -s "../libvmod_ip2location.la" "libvmod_ip2location.la" )
make[2]: Leaving directory '/root/IP2Location-Varnish/src'
make[2]: Entering directory '/root/IP2Location-Varnish'
rst2man README.rst vmod_ip2location.3
make[2]: Leaving directory '/root/IP2Location-Varnish'
make[1]: Leaving directory '/root/IP2Location-Varnish'

[ip2location]

Hi @jgarrouste,

We have managed to reproduce the issue on our side, and hence pushed a fix to this issue. Would you please try with our new release(https://github.com/ip2location/IP2Location-Varnish/releases/tag/1.0.4) in your machine and see if the issue gone?