issues with building QMYSQL plugin

SGaist

Out of curiosity, why don't you install the MySQL dev package from your distribution ? That would certainly simplify things.

As for your compiler, which version is it ?

mzimmers

MySQL doesn't make a package for Debian. The compiler is 4.9.2. I asked about updating the compiler in a Debian forum, and got a lot of snarky answers telling me it was a bad idea.

SGaist

Sure there is: see libmysqlclient-dev.

IIRC 4.9.2 should be good to build Qt 5.

mzimmers

@SGaist I'm sorry; I misunderstood you -- when you said "from your distribution," I thought you meant part of the Debian package.

Just to be clear, are you saying that with that package, I can better build the QMYSQL plugin, or that it's already included?

And, for my education, I'd really like to know how to alter compiler flags on the command line. I've tried "QMAKE_CXXFLAGS -=" but that doesn't seem to do anything.

Thanks.

SGaist

It will make things easier to build the plugin.

IIRC CONFIG += c++11 should only enable C++11 feature and not later.

mzimmers

@SGaist I think we're getting closer. I installed the package you referenced above, and ran this qmake command:

/opt/Qt/5.8/gcc_64/bin/qmake "INCLUDEPATH+=/usr/include" "LIBS+=-L/usr/lib/x86_64-linux-gnu/ -lmysqlclient_r" /home/mzimmers/QtStuff/qtbase/src/plugins/sqldrivers/mysql/mysql.pro/

I then edited the Makefile, changing the 2 occurrences of "-std=c++1z" to "-std=c++11" and ran make. Here's the output:

mzimmers@debian:~/QtStuff/qtbase/src/plugins/sqldrivers/mysql$ make
rm -f libqsqlmysql.so
g++ -Wl,--no-undefined -Wl,-O1 -Wl,--enable-new-dtags -Wl,-z,origin -Wl,-rpath,\$ORIGIN/../../lib -Wl,-rpath,\$ORIGIN/../../lib -shared -o libqsqlmysql.so .obj/qsql_mysql.o .obj/main.o .obj/moc_qsql_mysql_p.o  -L/usr/lib -lmysqlclient_r -L/opt/Qt/5.8/gcc_64/lib -lQt5Sql -lQt5Core -L/usr/lib64/mysql -lmysqlclient -lpthread -lz -lm -lssl -lcrypto -ldl  
/usr/bin/ld: cannot find -lmysqlclient_r
collect2: error: ld returned 1 exit status
Makefile:115: recipe for target '../../../../plugins/sqldrivers/libqsqlmysql.so' failed
make: *** [../../../../plugins/sqldrivers/libqsqlmysql.so] Error 1
mzimmers@debian:~/QtStuff/qtbase/src/plugins/sqldrivers/mysql$

I also tried LIBS+=-L/usr/lib/x86_64-linux-gnu (which is the actual directory) with the same results. Any idea what's wrong here?

Thank you.

SGaist

You shouldn't need the -l parameter

mzimmers

@SGaist OK, I removed it. Here are the results:

mzimmers@debian:~/QtStuff/qtbase/src/plugins/sqldrivers/mysql$ /opt/Qt/5.8/gcc_64/bin/qmake "INCLUDEPATH+=/usr/include" "LIBS+=-L/usr/lib/" ./mysql.pro
mzimmers@debian:~/QtStuff/qtbase/src/plugins/sqldrivers/mysql$ make
rm -f libqsqlmysql.so
g++ -Wl,--no-undefined -Wl,-O1 -Wl,--enable-new-dtags -Wl,-z,origin -Wl,-rpath,\$ORIGIN/../../lib -Wl,-rpath,\$ORIGIN/../../lib -shared -o libqsqlmysql.so .obj/qsql_mysql.o .obj/main.o .obj/moc_qsql_mysql_p.o  -L/usr/lib/ -L/opt/Qt/5.8/gcc_64/lib -lQt5Sql -lQt5Core -L/usr/lib64/mysql -lmysqlclient -lpthread -lz -lm -lssl -lcrypto -ldl  
/usr/bin/ld: cannot find -lz
/usr/bin/ld: cannot find -lssl
/usr/bin/ld: cannot find -lcrypto
collect2: error: ld returned 1 exit status
Makefile:115: recipe for target '../../../../plugins/sqldrivers/libqsqlmysql.so' failed
make: *** [../../../../plugins/sqldrivers/libqsqlmysql.so] Error 1
mzimmers@debian:~/QtStuff/qtbase/src/plugins/sqldrivers/mysql$

I don't know whether this is progress or a step back. Do I need to specify paths for the libraries that make can't find?

On a more general note: I notice that I seem to be needing to do a lot of things that aren't mentioned on the page that talks about building this plugin. Is the page incomplete, or is there something atypical about my Qt installation?

Thanks.

SGaist

You need the development packages for OpenSSL and zlib.

That's rather a side effect of the dependencies of the 3rd party that can change over time.

mzimmers

@SGaist so, I need these?

https://www.openssl.org/source/openssl-1.1.0e.tar.gz
http://www.zlib.net/zlib-1.2.11.tar.gz

They aren't explicitly labeled "development packages" but I'm hoping this is what I need...

SGaist

It seems you are forgetting you are running Linux ;)

Use your distributions package manager for that like you did to install the MySQL development package.

mzimmers

@SGaist believe it or not, I did look there first, but I wasn't sure what to choose. My best guesses would be:

openssl - Secure Sockets Layer toolkit - cryptographic utility
zlib1g-dev - compression library - development

(I found these among the results of an apt-cache search for openssl and zlib.)

Did I guess well?

SGaist

Sorry, it's libssl-dev the OpenSSL package is the command line client.
As for zlib, yes

mzimmers

I installed those two, and here is the output:```
mzimmers@debian:~/QtStuff/qtbase/src/plugins/sqldrivers/mysql$ make
rm -f libqsqlmysql.so
g++ -Wl,--no-undefined -Wl,-O1 -Wl,--enable-new-dtags -Wl,-z,origin -Wl,-rpath,$ORIGIN/../../lib -Wl,-rpath,$ORIGIN/../../lib -shared -o libqsqlmysql.so .obj/qsql_mysql.o .obj/main.o .obj/moc_qsql_mysql_p.o -L/usr/lib/x86_64-linux-gnu/ -lmysqlclient_r -L/opt/Qt/5.8/gcc_64/lib -lQt5Sql -lQt5Core -L/usr/lib64/mysql -lmysqlclient -lpthread -lz -lm -lssl -lcrypto -ldl
/usr/bin/ld: cannot find -lmysqlclient_r
collect2: error: ld returned 1 exit status
Makefile:115: recipe for target '../../../../plugins/sqldrivers/libqsqlmysql.so' failed
make: *** [../../../../plugins/sqldrivers/libqsqlmysql.so] Error 1
mzimmers@debian:~/QtStuff/qtbase/src/plugins/sqldrivers/mysql$

I have a file called "libmysqlclient_r.so.18" in /usr/lib/x86_64-linux-gnu...is this not the library it wants?

Thanks. I appreciate your staying up so late to help me with this.

SGaist

It looks like you didn't install the libmysqlclient-dev package.

mzimmers

@SGaist yes I did. I just tried again, and apt-get confirmed I'm up to date on this package. And according to the file list on the page you linked, the libraries are in the right location:

mzimmers@debian:/usr/lib/x86_64-linux-gnu$ pwd
/usr/lib/x86_64-linux-gnu
mzimmers@debian:/usr/lib/x86_64-linux-gnu$ ls libmy*
libmysqlclient.a        libmysqlclient_r.so.18.0.0  libmysqlclient.so.18      libmysqlclient.so.20      libmysqlservices.a
libmysqlclient_r.so.18  libmysqlclient.so           libmysqlclient.so.18.0.0  libmysqlclient.so.20.3.4
mzimmers@debian:/usr/lib/x86_64-linux-gnu$

SGaist

There's something strange here, you are missing at least the libmysqlclient_r.so symlink in that folder.

mzimmers

@SGaist I just did an apt-get remove and another install...same files. Should I file a bug report in the Debian forum?

SGaist

Since you have two sets of MySQL libraries there might be something else.

Can you post the result of dpkg -l | grep -i mysql ?

mzimmers

@SGaist :

mzimmers@debian:/usr/lib/x86_64-linux-gnu$ sudo dpkg -l | grep -i mysql
[sudo] password for mzimmers:
ii libmysqlclient-dev 5.7.17-1debian8 amd64 MySQL development headers
ii libmysqlclient18:amd64 5.5.54-0+deb8u1 amd64 MySQL database client library
ii libmysqlclient20:amd64 5.7.17-1debian8 amd64 MySQL shared client libraries
ii libmysqlcppconn7 1.1.3-6 amd64 MySQL Connector for C++ (library)
ii libqt5sql5-mysql:amd64 5.3.2+dfsg-4+deb8u2 amd64 Qt 5 MySQL database driver
ii mysql-apt-config 0.8.3-1 all Auto configuration for MySQL APT Repo.
ii mysql-client 5.7.17-1debian8 amd64 MySQL Client meta package depending on latest version
ii mysql-common 5.7.17-1debian8 amd64 MySQL Common
ii mysql-community-client 5.7.17-1debian8 amd64 MySQL Client
ii mysql-community-server 5.7.17-1debian8 amd64 MySQL Server
ii mysql-community-source 5.7.17-1debian8 amd64 MySQL source
ii mysql-server 5.7.17-1debian8 amd64 MySQL Server meta package depending on latest version
ii mysql-workbench 6.2.3+dfsg-7 amd64 MySQL Workbench - a visual database modeling, administration and queuing tool
ii mysql-workbench-data 6.2.3+dfsg-7 all MySQL Workbench -- architecture independent data
ii python-mysql.connector 1.2.3-2 all pure Python implementation of MySQL Client/Server protocol
mzimmers@debian:/usr/lib/x86_64-linux-gnu$