title: building python 3.6.3 from scratch on openSUSE
body: <p>I've been having a hard time building python 3.6.3 from source on openSUSE LEAP 42.3.<br>
  When I started configuring the build I ran:</p>
  
  <pre><code>./configure --prefix=/opt/python3.6 --with-pydebug --enable-optimizations --enable-shared
  </code></pre>
  
  <p>and in another rendition</p>
  
  <pre><code>./configure --prefix=/opt/python3.6 --with-pydebug --enable-optimizations --enable-shared --with-system-expat --with-system-ffi
  </code></pre>
  
  <p>prior to both, CXX was defined with </p>
  
  <pre><code>CXX = "/usr/bin/g++"
  </code></pre>
  
  <p>Configuration goes well (or it seems to) and then when I start make, after some success, it ALWAYS fails with this:</p>
  
  <blockquote>
    <p>gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3
    -Wall -Wstrict-prototypes    -std=c99 -Wextra -Wno-unused-result -Wno-unused-parameter -Wno-missing-field-initializers   -I. -I./Include    -DPy_BUILD_CORE  -I./Modules/expat -DHAVE_EXPAT_CONFIG_H -DUSE_PYEXPAT_CAPI -c ./Modules/expat/xmlparse.c -o Modules/xmlparse.o ./Modules/expat/xmlparse.c:92:3: error: #error You do not have support for any sources of high quality entropy
    enabled. For end user security, that is probably not what you want.
    Your options include: * Linux + glibc >=2.25 (getrandom):
    HAVE_GETRANDOM, * Linux + glibc &lt;2.25 (syscall SYS_getrandom):
    HAVE_SYSCALL_GETRANDOM, * BSD / macOS >=10.7 (arc4random_buf):
    HAVE_ARC4RANDOM_BUF, * BSD / macOS &lt;10.7 (arc4random):
    HAVE_ARC4RANDOM, * libbsd (arc4random_buf): HAVE_ARC4RANDOM_BUF +
    HAVE_LIBBSD, * libbsd (arc4random): HAVE_ARC4RANDOM + HAVE_LIBBSD, *
    Linux / BSD / macOS (/dev/urandom): XML_DEV_URANDOM * Windows
    (RtlGenRandom): _WIN32. If insist on not using any of these, bypass
    this error by defining XML_POOR_ENTROPY; you have been warned. If you
    have reasons to patch this detection code away or need changes to the
    build system, please open a bug. Thank you!</p>
  </blockquote>
  
  <p>I googled and I have yet to see something on this error.</p>
  
  <p>One last note.  I tried various permutations of ./configure, removing various feature flags but always keeping the prefix</p>
  
  <p>Can someone suggest WHY this is failing? (and how to fix it please)  This is the first time it has happened to me and I suspect very strongly that I had forgotten to install something, but expat and libexpat are all there.</p>
  
  <p>My thanks</p>