Macos – library not found for -lrt with QtCreator [mac os]

ccompilationcompiler-constructionmacosqt4

i'm getting some troubles with QT it builds with option "-lrt"

i'm using mac os 10.6 with QT creator 1.2.1, heeeeeeelp !

this is the full build command :

g++ -headerpad_max_install_names -o
AMiningCoreTest main.o tokenizer.o
DictionnaryToolBox.o mysql.o btree.o
BTreeDataTable.o tcaccess.o
-L/Library/Frameworks -L/usr/lib/mysql -lmysqlclient -L/usr/local/lib/ -ltokyocabinet -lz -lbz2 -lrt -lpthread -lm -lc

and it ends with

ld: library not found for -lrt
collect2: ld returned 1 exit status

Best Answer

The linker cannot find librt which is probably the Posix real time extensions library. I don't think this is available on OSX. Googling gives this from Apple developer lists

Question from list

I'm trying to build a simulator developed in my university (on Linux) and I get error by the linker that seems unable to find librt.a - in the code is used for clock_gettime() and I would like to know if there's a port of such library, or some other similar function that allows me to compile even on Mac OS X.

Answer librt.a is the System V name of the library containing the POSIX Advanced Realtime [RT} Option functions. The specific function you are asking about is part of the [TMR] option. If Mac OS X supported it, it would be in libSystem.B,dylib, not librt.a. The function in question is not supported by Mac OS X.

Your code should check to see whether optional to implement things above and beyond the UNIX standard are implemented in the target OS, and if they aren't, use a different interface.

Related Solutions

MySQL Install: ERROR: Failed to build gem native extension

On Debian (or Ubuntu) systems, just install libmysqlclient-dev package using:

sudo apt-get install libmysqlclient-dev

and then:

gem install mysql

It will be installed without any error.

Mysql – brew install thesql on macOS

I think one can end up in this position with older versions of mysql already installed. I had the same problem and none of the above solutions worked for me. I fixed it thus:

Used brew's remove & cleanup commands, unloaded the launchctl script, then deleted the mysql directory in /usr/local/var, deleted my existing /etc/my.cnf (leave that one up to you, should it apply) and launchctl plist

Updated the string for the plist. Note also your alternate security script directory will be based on which version of MySQL you are installing.

Step-by-step:

brew remove mysql

brew cleanup

launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

rm ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

sudo rm -rf /usr/local/var/mysql

I then started from scratch:

installed mysql with brew install mysql

ran the commands brew suggested: (see note: below)

unset TMPDIR

mysql_install_db --verbose --user=`whoami` --basedir="$(brew --prefix mysql)" --datadir=/usr/local/var/mysql --tmpdir=/tmp

Start mysql with mysql.server start command, to be able to log on it

Used the alternate security script:

/usr/local/Cellar/mysql/5.5.10/bin/mysql_secure_installation

Followed the launchctl section from the brew package script output such as,

#start
launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

#stop
launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

Note: the --force bit on brew cleanup will also cleanup outdated kegs, think it's a new-ish homebrew feature.

Note the second: a commenter says step 2 is not required. I don't want to test it, so YMMV!

Best Answer

Related Solutions

MySQL Install: ERROR: Failed to build gem native extension

Mysql – brew install thesql on macOS

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