C:\Users\Desktop\RailsSample\first-rails>gem install sqlite3 --platform ruby
Temporarily enhancing PATH for MSYS/MINGW...
Installing required msys2 packages: mingw-w64-x86_64-sqlite3
警告: mingw-w64-x86_64-sqlite3-3.25.2-1 は最新です -- スキップ
Building native extensions. This could take a while...
ERROR:  Error installing sqlite3:
        ERROR: Failed to build gem native extension.

    current directory: C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/sqlite3-1.4.0/ext/sqlite3
C:/Ruby25-x64/bin/ruby.exe -r ./siteconf20190412-5832-177unhn.rb extconf.rb
checking for sqlite3.h... yes
checking for pthread_create() in -lpthread... yes
checking for -ldl... no
checking for dlopen()... no
missing function dlopen
*** 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=C:/Ruby25-x64/bin/$(RUBY_BASE_NAME)
        --with-sqlcipher
        --without-sqlcipher
        --with-sqlite3-config
        --without-sqlite3-config
        --with-pkg-config
        --without-pkg-config
        --with-sqlcipher
        --without-sqlcipher
        --with-sqlite3-dir
        --without-sqlite3-dir
        --with-sqlite3-include
        --without-sqlite3-include=${sqlite3-dir}/include
        --with-sqlite3-lib
        --without-sqlite3-lib=${sqlite3-dir}/lib
        --with-pthreadlib
        --without-pthreadlib
        --with-dllib
        --without-dllib

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

  C:/Ruby25-x64/lib/ruby/gems/2.5.0/extensions/x64-mingw32/2.5.0/sqlite3-1.4.0/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/sqlite3-1.4.0 for inspection.
Results logged to C:/Ruby25-x64/lib/ruby/gems/2.5.0/extensions/x64-mingw32/2.5.0/sqlite3-1.4.0/gem_make.out