Develop Reference

PyAudio installation always fails on Mac

Firstly, I tried
pip install pyaudio
But that didn't work... I found that I need PortAudio, so installed it with brew:
brew install portaudio
That worked and then I restarted my Mac.
But pip install pyaudio still doesn't work and I get the below error message:
ERROR: Command errored out with exit status 1:
command: /Applications/Xcode.app/Contents/Developer/usr/bin/python3 -u -c
'import sys, setuptools, tokenize; sys.argv[0] =
'"'"'/private/var/folders/12/44t6pktj77xbqmyp7x368tdr0000gn/T/pip-install-gvxfbjmp/pyaudio/setup.py'"'"';
file='"'"'/private/var/folders/12/44t6pktj77xbqmyp7x368tdr0000gn/T/pip-install-gvxfbjmp/pyaudio/setup.py'"'"';f=getattr(tokenize,
'"'"'open'"'"', open)(file);code=f.read().replace('"'"'\r\n'"'"',
'"'"'\n'"'"');f.close();exec(compile(code, file, '"'"'exec'"'"'))'
bdist_wheel -d
/private/var/folders/12/44t6pktj77xbqmyp7x368tdr0000gn/T/pip-wheel-gvmpobvy
cwd: /private/var/folders/12/44t6pktj77xbqmyp7x368tdr0000gn/T/pip-install-gvxfbjmp/pyaudio/
Complete output (16 lines):
running bdist_wheel
running build
running build_py
creating build
creating build/lib.macosx-10.14-x86_64-3.7
copying src/pyaudio.py -> build/lib.macosx-10.14-x86_64-3.7
running build_ext
building '_portaudio' extension
creating build/temp.macosx-10.14-x86_64-3.7
creating build/temp.macosx-10.14-x86_64-3.7/src
xcrun -sdk macosx clang -arch x86_64 -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -iwithsysroot/System/Library/Frameworks/System.framework/PrivateHeaders
-iwithsysroot/Applications/Xcode.app/Contents/Developer/Library/Frameworks/Python3.framework/Versions/3.7/Headers
-DMACOSX=1 -I/Applications/Xcode.app/Contents/Developer/Library/Frameworks/Python3.framework/Versions/3.7/include/python3.7m
-c src/_portaudiomodule.c -o build/temp.macosx-10.14-x86_64-3.7/src/_portaudiomodule.o
src/_portaudiomodule.c:29:10: fatal error: 'portaudio.h' file not found
#include "portaudio.h"
^~~~~~~~~~~~~
1 error generated.
error: command 'xcrun' failed with exit status 1
----------------------------------------
ERROR: Failed building wheel for pyaudio
I also tried pip3 install pyaudio without any luck.
BTW I am just doing this because I want to use the Python Speech Recognition API and I think pyaudio is necessary... is it?

Very likely you need to specify the directory path where the compiler can find the source programs like portaudio.h.
Under assumption that the headers are in /usr/local/include directory, try to run the below command in the Terminal:
pip install --global-option='build_ext' --global-option='-I/usr/local/include' --global-option='-L/usr/local/lib' pyaudio

your problem is that with the Xcode command-line. Reinstall using this
xcode-select --install
after xcode is fixed the command('xcrun') should be able to run so just reuse
pip3 install pyaudio

you may need to upgrade pip
python3 -m pip install --upgrade pip
-- Successfully installed pip-21.2.4
and/or invoke pip3
pip3 install ...

command 'cc' failed with exit status 1 on OSX High Sierra

I'm trying to run on Mac Os high Sierra
pip install MySQL-python
But I'm getting
error: command 'cc' failed with exit status 1
I already tried the solution on this topic, but it didn't work.
This is the full error message
The directory '/Users/filipeferminiano/Library/Caches/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/Users/filipeferminiano/Library/Caches/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Collecting MySQL-python
Downloading https://files.pythonhosted.org/packages/a5/e9/51b544da85a36a68debe7a7091f068d802fc515a3a202652828c73453cad/MySQL-python-1.2.5.zip (108kB)
100% |████████████████████████████████| 112kB 289kB/s
Installing collected packages: MySQL-python
Running setup.py install for MySQL-python ... error
Complete output from command /System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python -u -c "import setuptools, tokenize;__file__='/private/tmp/pip-install-8I1X5u/MySQL-python/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /private/tmp/pip-record-z5HohX/install-record.txt --single-version-externally-managed --compile:
running install
running build
running build_py
creating build
creating build/lib.macosx-10.13-intel-2.7
copying _mysql_exceptions.py -> build/lib.macosx-10.13-intel-2.7
creating build/lib.macosx-10.13-intel-2.7/MySQLdb
copying MySQLdb/__init__.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb
copying MySQLdb/converters.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb
copying MySQLdb/connections.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb
copying MySQLdb/cursors.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb
copying MySQLdb/release.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb
copying MySQLdb/times.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb
creating build/lib.macosx-10.13-intel-2.7/MySQLdb/constants
copying MySQLdb/constants/__init__.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb/constants
copying MySQLdb/constants/CR.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb/constants
copying MySQLdb/constants/FIELD_TYPE.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb/constants
copying MySQLdb/constants/ER.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb/constants
copying MySQLdb/constants/FLAG.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb/constants
copying MySQLdb/constants/REFRESH.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb/constants
copying MySQLdb/constants/CLIENT.py -> build/lib.macosx-10.13-intel-2.7/MySQLdb/constants
running build_ext
building '_mysql' extension
creating build/temp.macosx-10.13-intel-2.7
cc -fno-strict-aliasing -fno-common -dynamic -arch x86_64 -arch i386 -g -Os -pipe -fno-common -fno-strict-aliasing -fwrapv -DENABLE_DTRACE -DMACOSX -DNDEBUG -Wall -Wstrict-prototypes -Wshorten-64-to-32 -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DTRACE -arch i386 -arch x86_64 -pipe -Dversion_info=(1,2,5,'final',1) -D__version__=1.2.5 -I/usr/local/Cellar/mysql/8.0.11/include/mysql -I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c _mysql.c -o build/temp.macosx-10.13-intel-2.7/_mysql.o
_mysql.c:44:10: fatal error: 'my_config.h' file not found
#include "my_config.h"
^~~~~~~~~~~~~
1 error generated.
error: command 'cc' failed with exit status 1
----------------------------------------
Command "/System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python -u -c "import setuptools, tokenize;__file__='/private/tmp/pip-install-8I1X5u/MySQL-python/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /private/tmp/pip-record-z5HohX/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /private/tmp/pip-install-8I1X5u/MySQL-python/
This is the python
which python
/usr/bin/python
and this is the pip I'm using
which pip
/usr/local/bin/pip

First, are you sure you want to use MySQL-python? This is a mostly-dead project that's been semi-maintained for legacy support for the past half decade, and doesn't even work with current versions of MySQL. It wants 5.0 or maybe 5.1; the current version is 8.0, and even the current legacy version is 5.7.
Other options include:
mysql-connector, aka MySQLConnector/Python: This is the officially supported library, from MySQL/Oracle. It can be a bit slow, which doesn't matter for most projects, but it can sometimes. It also has a different API (although if you stick to DB-API 2 methods, the only difference is the connect call; beyond that it should just be low-level stuff that's different).
mysqlclient: This is the package that Django and some other frameworks use. It's an updated fork of MySQL-Python (with a few things from its abandoned successor, moist). It can even be configured to install itself as MySQLdb, the same name used by MySQL-python.
PyMySQL: A third-party package built to be as compatible as possible with the old MySQL-python but simpler and easier to maintain, and install.
cmysql, a fork of PyMySQL that's only slightly harder to install, but should be faster than it, or than mysql-connector.
Some linux distros—including, IIRC, recent versions of Ubuntu—provide a package named python-MySQLdb or similar that is not actually MySQL-python, but instead mysqlclient built with the install-as-MySQLdb option. So, if the only reason that you're trying to use MySQL-python is that it's what you were using on some Ubuntu box, it's probably not what you were using, and therefore not what you want.
Some of these alternative also require MySQL (specifically, MySQLConnector/C, aka libmysqlclient, and its development libraries), some don't—but they're all compatible with current versions. (Although there are some notes on 8.0 crypto changes in the docs for PyMySQL and cmysql, which you might want to read if you use 8.0.)
Anyway, if you really want MySQL-python, then you will need to install MySQL in a 5.x version. The INSTALL points you to MySQL downloads.
If you want 5.0 or 5.1, you will have to dig through the Downloads folder at one of the mirrors to find a source package and follow the instructions to build and install it, since there are no binary installers that work on current Macs.
If you want later 5.x versions—which, remember, are not supported by MySQL-python, but they might work—Oracle is still providing Mac binary installers for those. If you can't find them in the main downloads section, the mirrors' Downloads folder will have them. As of right now, 5.6 and 5.7 have binary installer packages that end with -macos10.13-x86_64.dmg.
However, you might be happier installing it with Homebrew. Follow the instructions on that page to install brew, then to use it to:
brew install mysql#5.5
MySQL-python also requires OpenSSL libraries, and Apple deliberately hides the ones used by the OS to prevent people from accidentally building code against an old version and not getting security updates. The newer libraries should all know how to handle this, but MySQL-python does not. The easiest way to install a usable OpenSSL is with Homebrew again:
brew install openssl
But don't just run that command and close the window. Read the output, because you have to do all the stuff it says if you want MySQL-python to build.

My issue was that I was using MySql Version 8.0.12. As soon as I downgraded to MySQL 5.7, it was installed perfectly. I used the following to delete the version 8 by following: https://gist.github.com/vitorbritto/0555879fe4414d18569d
The gist of the above was:
Check for MySQL processes with: ps -ax | grep mysql
Stop and kill any MySQL processes
brew remove mysql
brew cleanup
launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
sudo rm /usr/local/mysql
sudo rm -rf /usr/local/var/mysql
sudo rm -rf /usr/local/mysql*
sudo rm ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
sudo rm -rf /Library/StartupItems/MySQLCOM
sudo rm -rf /Library/PreferencePanes/My*
rm -rf ~/Library/PreferencePanes/My*
sudo rm -rf /Library/Receipts/mysql*
sudo rm -rf /Library/Receipts/MySQL*
sudo rm -rf /private/var/db/receipts/mysql
Restart your computer just to ensure any MySQL processes are killed
install mysql using brew: brew install mysql#5.7
Finally, pip install mysql-python

abamert's answer did not work for me. Though this did, you might try skipping the first step,
brew install mysql-connector-c
brew install mysql
brew link --overwrite mysql
pip install MySQL-python

Twisted compilation failed in Ubuntu 14.04

I am trying to install Crossbar in my ubuntu 14.04. I installed the
dependencies as per the instruction here. When I am trying to
install cross the twisted installation fails. I am having python
2.7.6. I installed all the python-devl packages and all are up to date. I am getting the below error when I execute "pip install
crossbar".
copying twisted/internet/iocpreactor/iocpsupport/winsock_pointers.c -> build/lib.linux-i686-2.7/twisted/internet/iocpreactor/iocpsupport
copying twisted/python/sendmsg.c -> build/lib.linux-i686-2.7/twisted/python
copying twisted/test/raiser.c -> build/lib.linux-i686-2.7/twisted/test
running build_ext
cc -O2 -fPIC -Wimplicit -I/usr/lib/pypy/include -c conftest.c -o conftest.o
building 'twisted.runner.portmap' extension
creating build/temp.linux-i686-2.7
creating build/temp.linux-i686-2.7/twisted
creating build/temp.linux-i686-2.7/twisted/runner
cc -O2 -fPIC -Wimplicit -I/usr/lib/pypy/include -c twisted/runner/portmap.c -o build/temp.linux-i686-2.7/twisted/runner/portmap.o
twisted/runner/portmap.c:10:20: fatal error: Python.h: No such file or directory
include <Python.h>
compilation terminated.error: command 'cc' failed with exit status 1

Do you have the dev files installed from pypy? I don't use Ubuntu, but I believe the package is called pypy-dev. I contains a proper Python.h.
The one you mention belongs to the main Python installation. /usr/include/python2.7/Python.h

pip install: Command clang failed [duplicate]

Python library gevent, version 0.13.6 (the current version on PyPI) will not pip install on OS X Lion, Python 2.7 (and probably others.) It works fine on Snow Leopard.
How can I get this library installed?
Bonus points if it can be done using pip install, rather than a manual or custom process, because then it will play nicely with automated builds.
Here is my pip install output:
pip install gevent
Downloading/unpacking gevent
Running setup.py egg_info for package gevent
Requirement already satisfied (use --upgrade to upgrade): greenlet in ./tl_env/lib/python2.7/site-packages (from gevent)
Installing collected packages: gevent
Running setup.py install for gevent
building 'gevent.core' extension
gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -isysroot /Developer/SDKs/MacOSX10.6.sdk -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c gevent/core.c -o build/temp.macosx-10.6-intel-2.7/gevent/core.o
In file included from gevent/core.c:225:
gevent/libevent.h:9:19: error: event.h: No such file or directory
gevent/libevent.h:38:20: error: evhttp.h: No such file or directory
gevent/libevent.h:39:19: error: evdns.h: No such file or directory
gevent/core.c:361: error: field ‘ev’ has incomplete type
gevent/core.c:741: warning: parameter names (without types) in function declaration
gevent/core.c: In function ‘__pyx_f_6gevent_4core___event_handler’:
gevent/core.c:1619: error: ‘EV_READ’ undeclared (first use in this function)
gevent/core.c:1619: error: (Each undeclared identifier is reported only once
gevent/core.c:15376: warning: assignment makes pointer from integer without a cast
[... about 1000 more lines of compiler errors...]
gevent/core.c:15385: error: dereferencing pointer to incomplete type
gevent/core.c: In function ‘__pyx_pf_6gevent_4core_4http___init__’:
gevent/core.c:15559: warning: assignment makes pointer from integer without a cast
gevent/core.c: At top level:
gevent/core.c:21272: error: expected ‘)’ before ‘val’
lipo: can't figure out the architecture type of: /var/folders/s5/t94kn0p10hdgxzx9_9sprpg40000gq/T//cczk54q7.out
error: command 'gcc-4.2' failed with exit status 1
Complete output from command /Users/jacob/code/toplevel/tl_env/bin/python -c "import setuptools;__file__='/Users/jacob/code/toplevel/tl_env/build/gevent/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --single-version-externally-managed --record /var/folders/s5/t94kn0p10hdgxzx9_9sprpg40000gq/T/pip-s2hPd3-record/install-record.txt --install-headers /Users/jacob/code/toplevel/tl_env/bin/../include/site/python2.7:
running install
running build
running build_py
running build_ext
building 'gevent.core' extension
gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -isysroot /Developer/SDKs/MacOSX10.6.sdk -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c gevent/core.c -o build/temp.macosx-10.6-intel-2.7/gevent/core.o

Don't post the entire thing! That's too much! 90% of the time, the first error is enough...
gevent/libevent.h:9:19: error: event.h: No such file or directory
This means that the library which provides the event.h header is not installed. The library is called libevent (website).
In general, compilation errors like these are a flaw in the build scripts. The build script should give an error message that libevent is not installed, and it is a bug that it did not do so.
To get libevent from MacPorts and then manually tell compiler with CFLAGS environment variable where to find event.h and libevent while running pip.
sudo port install libevent
CFLAGS="-I /opt/local/include -L /opt/local/lib" pip install gevent
You can also use homebrew for installing libevent : brew install libevent
(from David Wolever's comment)

CFLAGS='-std=c99' pip install gevent
See in: Can't install gevent OSX 10.11
on OS X 10.11, clang uses c11 as the default, so just turn it back to c99.

After a while, I realized that the paths for the CFLAGS variable mentioned above works when installing libevent from port, but not from brew. The following worked for me (on OSX Mavericks):
$ brew install libevent
$ export CFLAGS="-I /usr/local/Cellar/libevent/2.0.21/include -L /usr/local/Cellar/libevent/2.0.21/lib"
$ pip install gevent

This is the way I found the easiest:
install libevent using homebrew
$ brew install libevent
install gevent
$ pip install gevent
This was the only way I could get it to work.

Found this answer when looking for help installing on Snow Leopard, posting this in case someone else comes this way with the same problem.
I had libevent installed via macports.
export CFLAGS=-I/opt/local/include
export LDFLAGS=-L/opt/local/lib
sudo pip install gevent

I had libevent installed via brew and it failed too, what worked was similar to what Stephen done, but pointing to brew default install:
CFLAGS=-I/usr/local/include LDFLAGS=-L/usr/local/lib pip install gevent

In case you install all from sources and use csh the following works on mac os 10.9
download latest stable http://libevent.org/ libevent-2.0.21-stable
./configure
make
sudo make install
virtualenv env
source env/bin/activate.csh
setenv CFLAGS "-I /usr/local/include -L /usr/local/lib"
pip install gevent

I use virtualenv and virtualenv wrapper, and so I wanted this to be self contained. I got gevent working like so:
Assuming you have virtual env setup, then:
workon {my_virtual_env}
Then download libevent and install it against the virtualenv.
curl -L -O https://github.com/downloads/libevent/libevent/libevent-2.0.21-stable.tar.gz
tar -xzf libevent-2.0.21-stable.tar.gz
cd libevent-2.0.21-stable
./configure --prefix="$VIRTUAL_ENV"
make && make install
I'm assuming you've got gcc 5+ installed (I use brew)
Hope this helps.

sudo pip install cython git+git://github.com/gevent/gevent.git#egg=gevent

I am using MacOs High Sierra (10.13.3)
First I did :
brew install libevent
I upgraded my pip version to pip-18.0.
then tried installing again with following :-
pip install gevent
it worked.

How can I install the Python library 'gevent' on Mac OS X Lion

Python library gevent, version 0.13.6 (the current version on PyPI) will not pip install on OS X Lion, Python 2.7 (and probably others.) It works fine on Snow Leopard.
How can I get this library installed?
Bonus points if it can be done using pip install, rather than a manual or custom process, because then it will play nicely with automated builds.
Here is my pip install output:
pip install gevent
Downloading/unpacking gevent
Running setup.py egg_info for package gevent
Requirement already satisfied (use --upgrade to upgrade): greenlet in ./tl_env/lib/python2.7/site-packages (from gevent)
Installing collected packages: gevent
Running setup.py install for gevent
building 'gevent.core' extension
gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -isysroot /Developer/SDKs/MacOSX10.6.sdk -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c gevent/core.c -o build/temp.macosx-10.6-intel-2.7/gevent/core.o
In file included from gevent/core.c:225:
gevent/libevent.h:9:19: error: event.h: No such file or directory
gevent/libevent.h:38:20: error: evhttp.h: No such file or directory
gevent/libevent.h:39:19: error: evdns.h: No such file or directory
gevent/core.c:361: error: field ‘ev’ has incomplete type
gevent/core.c:741: warning: parameter names (without types) in function declaration
gevent/core.c: In function ‘__pyx_f_6gevent_4core___event_handler’:
gevent/core.c:1619: error: ‘EV_READ’ undeclared (first use in this function)
gevent/core.c:1619: error: (Each undeclared identifier is reported only once
gevent/core.c:15376: warning: assignment makes pointer from integer without a cast
[... about 1000 more lines of compiler errors...]
gevent/core.c:15385: error: dereferencing pointer to incomplete type
gevent/core.c: In function ‘__pyx_pf_6gevent_4core_4http___init__’:
gevent/core.c:15559: warning: assignment makes pointer from integer without a cast
gevent/core.c: At top level:
gevent/core.c:21272: error: expected ‘)’ before ‘val’
lipo: can't figure out the architecture type of: /var/folders/s5/t94kn0p10hdgxzx9_9sprpg40000gq/T//cczk54q7.out
error: command 'gcc-4.2' failed with exit status 1
Complete output from command /Users/jacob/code/toplevel/tl_env/bin/python -c "import setuptools;__file__='/Users/jacob/code/toplevel/tl_env/build/gevent/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --single-version-externally-managed --record /var/folders/s5/t94kn0p10hdgxzx9_9sprpg40000gq/T/pip-s2hPd3-record/install-record.txt --install-headers /Users/jacob/code/toplevel/tl_env/bin/../include/site/python2.7:
running install
running build
running build_py
running build_ext
building 'gevent.core' extension
gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -isysroot /Developer/SDKs/MacOSX10.6.sdk -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c gevent/core.c -o build/temp.macosx-10.6-intel-2.7/gevent/core.o

Don't post the entire thing! That's too much! 90% of the time, the first error is enough...
gevent/libevent.h:9:19: error: event.h: No such file or directory
This means that the library which provides the event.h header is not installed. The library is called libevent (website).
In general, compilation errors like these are a flaw in the build scripts. The build script should give an error message that libevent is not installed, and it is a bug that it did not do so.
To get libevent from MacPorts and then manually tell compiler with CFLAGS environment variable where to find event.h and libevent while running pip.
sudo port install libevent
CFLAGS="-I /opt/local/include -L /opt/local/lib" pip install gevent
You can also use homebrew for installing libevent : brew install libevent
(from David Wolever's comment)

CFLAGS='-std=c99' pip install gevent
See in: Can't install gevent OSX 10.11
on OS X 10.11, clang uses c11 as the default, so just turn it back to c99.

After a while, I realized that the paths for the CFLAGS variable mentioned above works when installing libevent from port, but not from brew. The following worked for me (on OSX Mavericks):
$ brew install libevent
$ export CFLAGS="-I /usr/local/Cellar/libevent/2.0.21/include -L /usr/local/Cellar/libevent/2.0.21/lib"
$ pip install gevent

This is the way I found the easiest:
install libevent using homebrew
$ brew install libevent
install gevent
$ pip install gevent
This was the only way I could get it to work.

Found this answer when looking for help installing on Snow Leopard, posting this in case someone else comes this way with the same problem.
I had libevent installed via macports.
export CFLAGS=-I/opt/local/include
export LDFLAGS=-L/opt/local/lib
sudo pip install gevent

I had libevent installed via brew and it failed too, what worked was similar to what Stephen done, but pointing to brew default install:
CFLAGS=-I/usr/local/include LDFLAGS=-L/usr/local/lib pip install gevent

In case you install all from sources and use csh the following works on mac os 10.9
download latest stable http://libevent.org/ libevent-2.0.21-stable
./configure
make
sudo make install
virtualenv env
source env/bin/activate.csh
setenv CFLAGS "-I /usr/local/include -L /usr/local/lib"
pip install gevent

I use virtualenv and virtualenv wrapper, and so I wanted this to be self contained. I got gevent working like so:
Assuming you have virtual env setup, then:
workon {my_virtual_env}
Then download libevent and install it against the virtualenv.
curl -L -O https://github.com/downloads/libevent/libevent/libevent-2.0.21-stable.tar.gz
tar -xzf libevent-2.0.21-stable.tar.gz
cd libevent-2.0.21-stable
./configure --prefix="$VIRTUAL_ENV"
make && make install
I'm assuming you've got gcc 5+ installed (I use brew)
Hope this helps.

sudo pip install cython git+git://github.com/gevent/gevent.git#egg=gevent

I am using MacOs High Sierra (10.13.3)
First I did :
brew install libevent
I upgraded my pip version to pip-18.0.
then tried installing again with following :-
pip install gevent
it worked.