Can't install sqlite3 in conda environment

[CyanoKobalamyne]

In an existing conda environment, where sqlite is installed, gem install sqlite3 fails. This is despite sqlite3.h being in the conda environment's include dir, as well as the root environment's include dir and the system's include dir, /usr/include.

ERROR:  Error installing sqlite3:
        ERROR: Failed to build gem native extension.

    current directory: /home/[...]/.miniconda3/envs/[...]/lib/ruby/gems/2.5.0/gems/sqlite3-1.3.13/ext/sqlite3
/home/[...]/.miniconda3/envs/[...]/bin/ruby -r ./siteconf20180804-4558-2s2qdp.rb extconf.rb
checking for sqlite3.h... no
sqlite3.h is missing. Try 'brew install sqlite3',
'yum install sqlite-devel' or 'apt-get install libsqlite3-dev'
and check your shared library search path (the
location where your sqlite3 shared library is located).
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/home/[...]/.miniconda3/envs/[...]/bin/$(RUBY_BASE_NAME)
        --with-sqlite3-config
        --without-sqlite3-config
        --with-pkg-config
        --without-pkg-config
        --with-sqlite3-dir
        --without-sqlite3-dir
        --with-sqlite3-include
        --without-sqlite3-include=${sqlite3-dir}/include
        --with-sqlite3-lib
        --without-sqlite3-lib=${sqlite3-dir}/lib

To see why this extension failed to compile, please check the mkmf.log which can be found here:

  /home/[...]/.miniconda3/envs/[...]/lib/ruby/gems/2.5.0/extensions/x86_64-linux/2.5.0/sqlite3-1.3.13/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /home/[...]/.miniconda3/envs/[...]/lib/ruby/gems/2.5.0/gems/sqlite3-1.3.13 for inspection.
Results logged to /home/[...]/.miniconda3/envs/[...]/lib/ruby/gems/2.5.0/extensions/x86_64-linux/2.5.0/sqlite3-1.3.13/gem_make.out

[flavorjones]

We're working on shipping precompiled native gems as well as increasing test coverage for people who want to use system libraries. If you're curious please follow #320.