OpenCV Native Samples are not building

Issue

I have spent a long while trying to get this thing to work, and I think my error is very trivial but I have been unable to fix it. Plus, I know there have been questions about this before but none have helped me solve my issue.

I am using the android-opencv library in eclipse juno

When I build the sample, I will use sample 4 as an example, I get this message in my console:

15:29:35 **** Build of configuration Default for project org.opencv.samples.tutorial4.Sample4Mixed ****
"C:\\dev\\android-ndk-re8b-windows\\ndk-build.cmd" 
Cannot run program "C:\dev\android-ndk-re8b-windows\ndk-build.cmd": Launching failed

Error: Program "C:\dev\android-ndk-re8b-windows\ndk-build.cmd" not found in PATH
PATH=[C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files\Common Files\Microsoft Shared\Windows Live;C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\ThinkPad\Bluetooth Software\;C:\Program Files\ThinkPad\Bluetooth Software\syswow64;C:\Program Files\Broadcom\WHL\;C:\Program Files\Broadcom\WHL\syswow64;C:\Program Files\Broadcom\WHL\SysWow64\;C:\Program Files\Broadcom\WHL\SysWow64\syswow64;C:\Program Files (x86)\Common Files\Lenovo;C:\Program Files (x86)\Common Files\Ulead Systems\MPEG;C:\Program Files (x86)\Windows Live\Shared;C:\SWTOOLS\ReadyApps;C:\Program Files (x86)\Intel\Services\IPT\;C:\Program Files (x86)\MATLAB\R2011a Student\bin;c:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;c:\Program Files\Microsoft SQL Server\100\Tools\Binn\;c:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\Program Files\TortoiseSVN\bin;C:\Program Files (x86)\Git\cmd;C:\Program Files (x86)\QuickTime\QTSystem\;C:\Program Files (x86)\Symantec\VIP Access Client\;C:\Program Files (x86)\SSH Communications Security\SSH Secure Shell]

15:29:35 Build Finished (took 54ms)

Where are the double \'s coming from?!

Also I did define my environmental variable NDKROOT to be the absolute path to my ndk. But to be even more safe, I defined it again in my properties->c/c++ build path.

HELP

Solution

Try the following steps:

1. Head to the project's properties. If you're using Windows, the shortcut is Alt + Enter; or simply right-click the project name to find its properties.

2. Go to the C/C++ Build section; under Builder Settings tab in Build command: text box you're likely to find something similar to that below, if it's empty then type in the similar text - namely: ${NDKROOT}/ndk-build.cmd where NDKROOT, as its name implies, refers to the path where your NDK root folder exists.

3. Now you must inform eclipse what NDKROOT equates to; as in, where is the NDK root path. You can do this by heading to (in your project's properties) C/C++ Build > Environment > press Add…

4. Now add your environment variable named NDKROOT (the Name) with the relevant path (Value). Note that you're to repeat this per NDK project. You would get a window similar to that below.

5. Press OK to the New variable input window and then OK again to the properties window.

Answered By - Noha Kareem