I wanted to update my cmake version. So I had first uninstalled it and then tried to install as given in this post by teocci.
However, it was giving some errors on entering make and now I want to uninstall it and install the previous version of cmake. I tried sudo apt-get purge cmake. But it still remains in the system on entering cmake --version.
What should I do?
TL;DR: Run sudo make uninstall in the directory where you ran sudo make install before.
You followed this method of installing a different version of CMake. This is to say that you uninstalled the version provided by Ubuntu's package manager and manually downloaded, compiled, and installed it yourself from source code.
Assuming you were able to follow those instructions successfully, the version of CMake provided by Ubuntu's package manager (via the cmake package) is already uninstalled. Because the version that you have installed now is not provided by Ubuntu's package manager, but instead the version you compiled and installed yourself, running sudo apt-get purge cmake again does not remove it.
Since you installed cmake by compiling it and then running sudo make install, the solution is for you to:
cd to go back to the directory where you ran that command.sudo make uninstall.Not all software that can be installed by running make install has a corresponding uninstall target letting you run make uninstall to remove it. But CMake does support this.1
If you have deleted the folder in which you ran sudo make install, or otherwise changed it, then your best bet is to rebuild and reinstall it (be sure to use exactly the same version) to get back the ability to run sudo make uninstall. That is, you would follow the same installation steps, starting from the same .tar.gz file and passing all the same options you used (if any) to ./bootstrap. If you just ran ./bootstrap with no arguments after it, do that again. After running sudo make install again, which would (harmlessly) overwrite the files that were already installed with copies of themselves, you would then be able to use sudo make uninstall.
Another possible approach, which I strongly discourage you from doing, would be to try to figure out exactly what files and directories were created in the installation, and to try to remove just those files and directories but no others. If you did not pass the --prefix to ./bootstrap when you compiled CMake then it installed files in /usr/local, but it is not the only program that uses that directory. It would have installed files in the various subdirectories of /usr/local, such as bin and lib (and others), so aside from the situation where you know nothing else was installed into /usr/local, this option requires a lot of work.
1 It's easy to become confused about whether or not you can uninstall CMake by running sudo make uninstall because, by default, when you use CMake to create build scripts for your own software, no uninstall target is generated unless you explicitly ask for one. However, CMake itself is designed to be easily uninstalled, and its source code does define those uninstall targets for itself. In the Makefile generated from running ./bootstrap you can see:
#=============================================================================
# Target rules for targets named uninstall
# Build rule for target.
uninstall: cmake_check_build_system
$(MAKE) -f CMakeFiles/Makefile2 uninstall
.PHONY : uninstall
# fast build rule for target.
uninstall/fast:
$(MAKE) -f CMakeFiles/uninstall.dir/build.make CMakeFiles/uninstall.dir/build
.PHONY : uninstall/fast
You can also search for uninstall support in its CMakeLists.txt file.
To be sure, I tested this with CMake 3.9.0, and it does work. The uninstall target is generated and running sudo make uninstall works to uninstall CMake.
cmake command you installed yourself because it expected it to be at /usr/bin/cmake, which seems like a bug, but one that could be worked around. CMake 2.8.2 is quite old; Ubuntu 14.04 has CMake 2.8.12. What Ubuntu release are you running? What's the output of lsb_release -rd and apt-cache policy cmake | grep -oP 'Candidate: \K.+'? How did you download pybind11's source code, and what version is it (or did you check out the head from git)?
– Eliah Kagan
Aug 03 '17 at 18:56
.tar.gz file, the output of uname -m, and all info you've given in comments here, including release (14.04) and system-provided cmake version (2.8.12.2-0ubuntu3). If you comment here with a link to your new question, I'll look at it, though someone else might find and post a solution first.
– Eliah Kagan
Aug 03 '17 at 19:21
/usr/bin/cmake and is still using it, and if you reinstall pybind11 it will see wherever cmake is now. But that is just a guess and there may be other more effective, easier, or otherwise better solutions. I still recommend you post a new question about this. conda is a good way to install Python tools and it is likely better than Git for installing pybind11. I had mentioned Git only [a] to find out what version of pybind11 you have (this is still relevant) and [b] because I thought you couldn't install it successfully.
– Eliah Kagan
Aug 04 '17 at 08:55
/usr/local/bin/cmake. Or a quick fix may be to symlink /usr/bin/cmake to it. This could work if pybind11 isn't relying on the version of CMake it thinks is installed or where CMake's other files are (I don't know enough about pybind11 to tell without checking). Or you could rebuild CMake with a prefix /usr/bin and use checkinstall (as sudo make install with that prefix isn't safe). If you post a new question about making pybind11 use the new CMake, it will be easier to figure out and others may see it and help.
– Eliah Kagan
Aug 04 '17 at 09:17
update-alternatives for this! :) I'm glad the problem is solved.
– Eliah Kagan
Aug 04 '17 at 10:20
sudo apt-get purge cmakecommand. – AmeyaVS Aug 03 '17 at 16:47cmake --version?, and also what is the output of the commandwhich cmake? – AmeyaVS Aug 03 '17 at 17:03sudo make uninstallrun from the same place you ransudo make install. (Programs you create yourself and use CMake to generate build scripts for don't automatically support this, but I believe CMake does.) I'm compiling CMake now to test it, and I'll answer if it works or comment if it doesn't. Even if I'm mistaken that this works, I still recommend you wait a while for other answers before manually deleting files. – Eliah Kagan Aug 03 '17 at 17:38.tar.gzfile) and pass exactly the same options (if you used any) to./bootstrap, then when you install it, it will install the same files it had already installed (harmlessly overwriting them) and then you can runsudo make uninstall. But you may want to wait to try this until I've finished checking thatsudo make uninstalldoes actually work to uninstall CMake. (I'll make sure to mention this situation in my answer.) – Eliah Kagan Aug 03 '17 at 17:50sudo make uninstalldoes work but it still keeps the directory structure which one would might want to remove since they are empty directories. Sorry my bad for previous comments. – AmeyaVS Aug 03 '17 at 17:56