Rails installing mysql - Error installing mysql2: ERROR: Failed to build gem native extension

Question

I have a Rails 3.2.13 app that I would like deployed, but the hosting service would require MySQL, as opposed to sqlite which I have been using.

In the process of converting from sqlite to MySQL, I had to install the ruby gem mysql2, which is giving me the following error upon installing:

Error installing mysql2: ERROR: Failed to build gem native extension.

I've tried both bundle install, as well as gem install mysql2, but the same error message appeared.

I am aware that the solution that has worked for many is sudo apt-get install libmysql-ruby libmysqlclient-dev, but I'm using Git Bash on Windows, so I found a Windows equivalent (@francois's answer on this question). I installed MySQL Server 5.6 with the installer, and ran the following command:

gem install mysql2 -- '--with-mysql-lib="c:\Program Files\MySQL\MySQL Server 5.6\lib" --with-mysql-include="c:\Program Files\MySQL\MySQL Server 5.6\include"' 

From what I have read, this is supposed to successfully install the 'mysql2' ruby gem. But strangely enough, I still had the following error:

    Temporarily enhancing PATH to include DevKit... Building native extensions with: '--with-mysql-lib="c:\Program

Files\MySQL\MySQL Server 5.6\lib" --with-mysql-include="c:\Program Files\MySQL\MySQL Server 5.6\i nclude"' This could take a while... ERROR: Error installing mysql2: ERROR: Failed to build gem native extension.

        c:/RailsInstaller/Ruby1.9.3/bin/ruby.exe extconf.rb --with-mysql-lib="c:\Pro gram Files\MySQL\MySQL Server 5.6\lib" --with-mysql-include="c:\Program Files\My SQL\MySQL Server 5.6\include" checking for rb_thread_blocking_region()... yes checking for rb_wait_for_single_fd()... yes checking for rb_hash_dup()... yes

checking for rb_intern3()... yes checking for main() in -llibmysql... yes checking for mysql.h... yes checking for errmsg.h... yes checking for mysqld_error.h... yes creating Makefile

    make generating mysql2-i386-mingw32.def compiling client.c client.c: In function 'rb_raise_mysql2_error': client.c:139:3:

warning: ISO C90 forbids mixed declarations and code client.c: In function 'finish_and_mark_inactive': client.c:508:3: warning: ISO C90 forbids mixed declarations and code client.c: In function 'rb_mysql_client_abandon_results': client.c:535:3: warning: ISO C90 forbids mixed declarations and code client.c: In function 'rb_mysql_client_next_result': client.c:938:5: warning: ISO C90 forbids mixed declarations and code compiling mysql2_ext.c compiling result.c result.c: In function 'rb_mysql_result_fetch_fields': result.c:407:35: warning: comparison between signed and unsigned integer express ions linking shared-object mysql2/mysql2.so client.o: In function nogvl_connect': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:158: undefined reference tomysql_real_connect@32' client.o: In function nogvl_init': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:150: undefined reference tomysql_init@4' client.o: In function set_ssl_options': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:1078: undefined reference tomysql_ssl_set@24' client.o: In function mysql_client_options': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:723: undefined reference tomysql_options@12' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:727: undefined reference to mysql_error@4' client.o: In functionrb_mysql_info': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:267: undefined reference to mysql_info@4' client.o: In functionrb_mysql_client_warning_count': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:257: undefined reference to mysql_warning_count@4' client.o: In functionnogvl_do_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:370: undefined reference to mysql_store_result@4' client.o: In functionrb_mysql_client_more_results': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:923: undefined reference to mysql_more_results@4' client.o: In functionnogvl_select_db': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:863: undefined reference to mysql_select_db@8' client.o: In functionnogvl_ping': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:894: undefined reference to mysql_ping@4' client.o: In functionrb_mysql_client_thread_id': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:856: undefined reference to mysql_thread_id@4' client.o: In functionrb_mysql_client_last_id': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:825: undefined reference to mysql_insert_id@4' client.o: In functionnogvl_read_query_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:357: undefined reference to mysql_read_query_result@4' client.o: In functionrb_mysql_client_server_info': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:788: undefined reference to mysql_get_server_version@4' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:789: undefined reference tomysql_get_server_info@4' client.o: In function rb_mysql_client_info': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:756: undefined reference tomysql_get_client_version@0' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:757: undefined reference to mysql_get_client_info@0' client.o: In functionrb_mysql_client_real_escape': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:662: undefined reference to mysql_real_escape_string@16' client.o: In functionfinish_and_mark_inactive': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:515: undefined reference to mysql_free_result@4' client.o: In functionnogvl_send_query': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:334: undefined reference to mysql_send_query@12' client.o: In functionnogvl_close': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:190: undefined reference to mysql_close@4' client.o: In functionrb_mysql_client_escape': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:238: undefined reference to mysql_escape_string@12' client.o: In functionrb_raise_mysql2_error': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:125: undefined reference to mysql_error@4' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:126: undefined reference tomysql_sqlstate@4' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:140: undefined reference to mysql_errno@4' client.o: In functionrb_connect': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:297: undefined reference to mysql_errno@4' client.o: In functionrb_mysql_client_store_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:966: undefined reference to mysql_errno@4' client.o: In functionrb_mysql_client_next_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:939: undefined reference to mysql_next_result@4' client.o: In functionrb_mysql_client_affected_rows': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:839: undefined reference to mysql_affected_rows@4' client.o: In functionrb_mysql_client_async_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:419: undefined reference to mysql_errno@4' client.o: In functionrb_mysql_client_abandon_results': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:539: undefined reference to mysql_next_result@4' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:538: undefined reference tomysql_more_results@4' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:547: undefined reference to mysql_free_result@4' client.o: In functionnogvl_do_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:368: undefined reference to mysql_use_result@4' client.o: In functionnogvl_close': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:190: undefined reference to mysql_close@4' client.o: In functionset_charset_name': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:1067: undefined reference to mysql_options@12' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:1069: undefined reference tomysql_error@4' client.o: In function init_mysql2_client': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/cl ient.c:1105: undefined reference tomysql_get_client_info@0' result.o: In function rb_mysql_result_count': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:576: undefined reference tomysql_num_rows@4' result.o: In function rb_mysql_result_fetch_field': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:126: undefined reference tomysql_fetch_field_direct@8' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:114: undefined reference to mysql_num_fields@4' result.o: In functionrb_mysql_result_fetch_fields': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:403: undefined reference to mysql_num_fields@4' result.o: In functionnogvl_fetch_row': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:105: undefined reference to mysql_fetch_row@4' result.o: In functionrb_mysql_result_free_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:75: undefined reference to mysql_free_result@4' result.o: In functionrb_mysql_result_fetch_row': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:213: undefined reference to mysql_fetch_lengths@4' c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:215: undefined reference tomysql_num_fields@4' result.o: In function rb_mysql_result_each': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:503: undefined reference tomysql_fetch_fields@4' result.o: In function rb_mysql_result_free_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:75: undefined reference tomysql_free_result@4' result.o: In function rb_mysql_result_each': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:531: undefined reference tomysql_fetch_fields@4' result.o: In function rb_mysql_result_free_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:75: undefined reference tomysql_free_result@4' result.o: In function rb_mysql_result_each': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:490: undefined reference tomysql_num_rows@4' result.o: In function rb_mysql_result_free_result': c:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\mysql2-0.3.13\ext\mysql2/re sult.c:75: undefined reference tomysql_free_result@4' collect2: ld returned 1 exit status make: *** [mysql2.so] Error 1

    Gem files will remain installed in c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9 .1/gems/mysql2-0.3.13

for inspection. Results logged to c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0. 3.13/ext/mysql2/gem_make.out

Can anyone please help?  I am having much trouble comprehending what's wrong with the installation.

Answer 1

I had this same error on Win64 environment.

I tested a lot of solutions but the only that worked for me was:

• gem install mysql2 -v '0.3.11'

Answer 2

I've been so annoyed by the same problem, and finally succeeded in installing mysql2. Kudos to odiszapc@github. It appears any other solution I've found via Google than below doesn't work to me.

Copied and pasted from here. So no credit to me.

gem uninstall mysql2

Download last MySQL connector from http://cdn.mysql.com/Downloads/Connector-C/mysql-    connector-c-noinstall-6.0.2-win32.zip

Extract it to C:\connector-6.0.2

gem install mysql2 --platform=ruby -- '--with-mysql-lib="C:\connector-6.0.2\lib" --with-mysql-include="C:\connector-6.0.2\include" --with-mysql-dir="C:\connector-6.0.2"'

Additional info on mine.

• ruby 1.9.3p392 (2013-02-22) [i386-mingw32]
• Rails 3.2.13
• MySQL Server 5.6
• mysql2-0.3.13

P.S Even if you successfully installed mysql2, you may still need some work (e.g. mysql2.so (LoadError)), and it has something do with libmysql in my case, and seems like yet another major glitch about mysql2.

Answer 3

I am installing on Windows 7 64 bit. What worked for me was:

Download the C 32 bit connector archive from: http://dev.mysql.com/downloads/connector/c/

I extracted it to C:\Temp. If you use a different directory, adjust the next command.

gem install mysql2 --platform=ruby -- '--with-mysql-dir="C:\Temp\mysql-connector-c-6.1.3-win32"'

Answer 4

pain... lot of pain. Finally working doing:

(Platform: Windows64bits, Ruby32bits, DevKit32bits...)

1. Download mysql connector for C from http://dev.mysql.com/get/Downloads/Connector-C/mysql-connector-c-noinstall-6.0.2-win32.zip/from/pick
2. Unzip connector in a directory without spaces in names!
3. Copy lib/libmysql.dll file into ruby/bin one
4. gem install mysql2 -- --with-mysql-dir=D:\RoR\mysql-connector-c (so give the dir of connector and not the dir of server)

And I got mysql2 v0.3.17 up and running...

Answer 5

1. Download Mysql connector from
   http://dev.mysql.com/get/Downloads/Connector-C/mysql-connector-c-noinstall-6.0.2-win32.zip/from/pick.
2. Extract it. copy lib\libmysql.dll file and paste it in Ruby's bin directory ex: C:\RailsInstaller\Ruby1.9.3\bin
3. Now again install Mysql2 gem
   gem install mysql2 -- '--with-mysql-lib="c:\Program Files\MySQL\MySQL Server 5.0\lib\opt" --with-mysql-include="c:\Program Files\MySQL\MySQL Server 5.0\include"'
   note: change mysql installation path as per yours
4. Try to bundle now