title: apache mod_http2 prerequisite failures
body: <p>I am trying to RPM build apache 2.4.18 with mod_http2 on CentOS 7.  However, when building I get the following failure:</p>
  
  <pre><code>checking whether to enable mod_http2... checking dependencies
  checking for nghttp2... checking for user-provided nghttp2 base directory... /usr/lib64
  checking for pkg-config along :/usr/lib64/pkgconfig:/usr/share/pkgconfig...   adding "-I/usr/lib64/include" to CPPFLAGS
    setting MOD_CFLAGS to "-I/usr/lib64/include"
    setting ab_CFLAGS to "-I/usr/lib64/include"
    adding "-L/usr/lib64/lib" to LDFLAGS
    setting MOD_LDFLAGS to "-L/usr/lib64/lib"
  checking for nghttp2 version &gt;= 1.2.1... FAILED
  configure: WARNING: nghttp2 version is too old
  no
  checking whether to enable mod_http2... configure: error: mod_http2 has been requested but can not be built due to prerequisite failures
  error: Bad exit status from /var/tmp/rpm-tmp.aOryWX (%build)
  
  
  RPM build errors:
      Bad exit status from /var/tmp/rpm-tmp.aOryWX (%build)
  </code></pre>
  
  <p>However, my nghttp2 and libnghttp2 versions are both 1.7.1:</p>
  
  <pre><code>Installed Packages
  Name        : nghttp2
  Arch        : x86_64
  Version     : 1.7.1
  Release     : 1.el7.centos
  Size        : 1.3 M
  Repo        : installed
  From repo   : local
  Summary     : Experimental HTTP/2 client, server and proxy
  URL         : https://nghttp2.org/
  Licence     : MIT
  Description : This package contains the HTTP/2 client, server and proxy programs.
  
  Installed Packages
  Name        : libnghttp2
  Arch        : x86_64
  Version     : 1.7.1
  Release     : 1.el7.centos
  Size        : 139 k
  Repo        : installed
  From repo   : local
  Summary     : A library implementing the HTTP/2 protocol
  URL         : https://nghttp2.org/
  Licence     : MIT
  Description : libnghttp2 is a library implementing the Hypertext Transfer Protocol
              : version 2 (HTTP/2) protocol in C.
  </code></pre>
  
  <p>From my <code>httpd.spec</code>, I have added the following configuration options:</p>
  
  <pre><code>%configure \
      --enable-layout=RPM \
      --libdir=%{_libdir} \
      --sysconfdir=%{_sysconfdir}/httpd/conf \
      --includedir=%{_includedir}/httpd \
      --libexecdir=%{_libdir}/httpd/modules \
      --datadir=%{contentdir} \
      --with-installbuilddir=%{_libdir}/httpd/build \
      --enable-mpms-shared=all \
      --with-apr=%{_prefix} --with-apr-util=%{_prefix} \
      --enable-suexec --with-suexec \
      --with-suexec-caller=%{suexec_caller} \
      --with-suexec-docroot=%{contentdir} \
      --with-suexec-logfile=%{_localstatedir}/log/httpd/suexec.log \
      --with-suexec-bin=%{_sbindir}/suexec \
      --with-suexec-uidmin=500 --with-suexec-gidmin=100 \
      --enable-pie \
      --with-pcre \
      --enable-mods-shared=all \
      --enable-ssl --with-ssl --enable-socache-dc --enable-bucketeer \
      --enable-case-filter --enable-case-filter-in \
      --enable-http --enable-http2 --with-nghttp2=%{_libdir} \
      --disable-imagemap
  </code></pre>
  
  <p>And my libnghttp2 is installed in /usr/lib64:</p>
  
  <pre><code>sudo find / -iname "*nghttp2*"
  [sudo] password for administrator: 
  /home/administrator/rpmbuild/RPMS/x86_64/nghttp2-1.7.1-1.el7.centos.x86_64.rpm
  /home/administrator/rpmbuild/RPMS/x86_64/libnghttp2-1.7.1-1.el7.centos.x86_64.rpm
  /home/administrator/rpmbuild/RPMS/x86_64/libnghttp2-devel-1.7.1-1.el7.centos.x86_64.rpm
  /home/administrator/rpmbuild/RPMS/x86_64/nghttp2-debuginfo-1.7.1-1.el7.centos.x86_64.rpm
  /home/administrator/rpmbuild/SRPMS/nghttp2-1.7.1-1.el7.src.rpm
  /var/lib/yum/yumdb/l/56527c0ccd96b61605f75b8cb07ebee7b2901c17-libnghttp2-1.7.1-1.el7.centos-x86_64
  /var/lib/yum/yumdb/n/4630c64bc127ec7ed9b842ee49923baa493c05b5-nghttp2-1.7.1-1.el7.centos-x86_64
  /var/repos/centos/7/nghttp2-1.7.1-1.el7.centos.x86_64.rpm
  /var/repos/centos/7/nghttp2-debuginfo-1.7.1-1.el7.centos.x86_64.rpm
  /var/repos/centos/7/libnghttp2-1.7.1-1.el7.centos.x86_64.rpm
  /var/repos/centos/7/libnghttp2-devel-1.7.1-1.el7.centos.x86_64.rpm
  /usr/lib64/libnghttp2.so.14
  /usr/lib64/libnghttp2.so.14.4.1
  /usr/share/licenses/libnghttp2-1.7.1
  /usr/share/nghttp2
  </code></pre>
  
  <p>The only file in <code>/usr/share/nghttp2</code> is <code>fetch-ocsp-response</code>.</p>
  
  <p>Hopefully I have provided sufficient information, but if more is needed please ask.  What is the problem and how do I fix it?</p>