why -Werror cause configure error

Question

I want build nginx from source. so I write a bash script to do this:

#!/bin/bash
export LD_LIBRARY_PATH="/usr/lib64:$LD_LIBRARY_PATH"
dir=$(realpath `dirname $BASH_SOURCE`)

cd $dir/modules
for folder in *
do
    ADD_MODULES="$ADD_MODULES \
    --add-module=$dir/modules/$folder"
done

cd $dir/nginx
./auto/configure \
--prefix=/usr/share/nginx \
--sbin-path=/usr/sbin/nginx \
--conf-path=/etc/nginx/nginx.conf \
--error-log-path=/var/log/nginx/error.log \
--http-log-path=/var/log/nginx/access.log \
--http-client-body-temp-path=/var/lib/nginx/tmp/client_body \
--http-proxy-temp-path=/var/lib/nginx/tmp/proxy \
--http-fastcgi-temp-path=/var/lib/nginx/tmp/fastcgi \
--http-uwsgi-temp-path=/var/lib/nginx/tmp/uwsgi \
--http-scgi-temp-path=/var/lib/nginx/tmp/scgi \
--pid-path=/run/nginx.pid \
--lock-path=/run/lock/subsys/nginx \
--user=nginx \
--group=nginx \
--with-file-aio \
--with-ipv6 \
--with-http_ssl_module \
--with-http_spdy_module \
--with-http_realip_module \
--with-http_addition_module \
--with-http_xslt_module \
--with-http_image_filter_module \
--with-http_geoip_module \
--with-http_stub_status_module \
--with-http_sub_module \
--with-http_dav_module \
--with-http_flv_module \
--with-http_mp4_module \
--with-http_gunzip_module \
--with-http_gzip_static_module \
--with-http_random_index_module \
--with-http_secure_link_module \
--with-http_degradation_module \
--with-http_stub_status_module \
--with-http_perl_module \
--with-mail \
--with-mail_ssl_module \
--with-pcre \
--with-debug \
$ADD_MODULES \
--with-cc-opt='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic' \
--with-ld-opt='-Wl,-z,relro -Wl,-E' 

if [ $? -ne 0 ]; then
    exit
fi

read -p 'Run make & make install? [Y/n]> ' RUN

if [ "x$RUN" = "x" -o "x$RUN" = "xY" -o "x$RUN" = "xy" ]; then
    make -j8
    make install
fi

when I run this script, configure success, but there is a warning treat as error(unused-but-set-variable) during compile and make exit with this error.

So, I edit "--with-cc-opt" option, change "-Wall" to "-Werror", this time configure fail with error

./auto/configure: error: the HTTP XSLT module requires the libxml2/libxslt
libraries. You can either do not enable the module or install the libraries.

Then I change "-Werror" to "-Werror=unused-but-set-variable", and configure fail with error

./auto/configure: no supported file AIO was found
Currently file AIO is supported on FreeBSD 4.3+ and Linux 2.6.22+ only

(I tried to delete -W option, but is same with -Wall)

Who knows why?!

EDIT:

I solve by editing nginx configure option files...

I noticed that the tail of make log

cc -c -pipe -O -W -Wall -Wpointer-arith -Wno-unused-parameter -Werror -g -O2 -g -pipe -Werror=unused-but-set-variable -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -I src/core -I (.... etc

I think these problem is nginx configure auto prepend some CC-opt bedore mine

so I use grep '\-Wall' ./auto -R and grep '\-Werror' ./auto -R found them and delete it.

now I have "complete" control of CC flag.

thanks for R's answer :D

Answer 1

First problem (error: the HTTP XSLT module requires the libxml2/libxslt) can be resolved by installing libxslt-devel packet.

Answer 2

Remove the --with-file-aio option. It's not useful.

Either remove the --with-http_xslt_module option or install libxml2 and libxslt.

In general, don't use --with and --enable options you don't understand.