yocto project runqemu: command not found

Issue

I am setting up my yocto project, for that i have followed these below steps:

1. download the Poky Source code (ubuntu: /yocto/source)
   $ git clone git://git.yoctoproject.org/poky
2. Checkout the latest branch/release (zeus)
   $ git checkout zeus
3. Step 3: Prepare the build environment (ubuntu: /yocto/source/poky)
   $ source oe-init-build-env ../../build
   The above script will move in a build folder and create two files in conf folder ( local.conf, bblayers.conf ) inside conf folder
4. Building Linux Distribution (unbuntu: /yoctu/build)
   $ bitbake core-image-minimal
5. Checking the runqemu (ubuntu: /yocto/source/poky/scripts)
   $ ls runqemu // and it is there
6. Run generated image in qemu (ubuntu: /yocto/build)
   $ runqemu qemux86-64 core-image-minimal

other window open for qemu and image runs well.
Problem
After using first time when i close the terminal, and use it again by running $ runqemu qemux86-64 core-image-minimal in (ubuntu: /yocto/build) error pops up runqemu: command not found and if i write bitbake in poky directory same error pops up bitbake: command not found.
NOTE: i have repeat this whole process 3 times to check if the installation is not correct but i have done everything fine from my side.

yocto project hierarchy:

Solution

If you close your poky environment terminal you always MUST re-source the environment.

The poky's oe-init-build-env setups up all commands for you, for instance:

runqemu* commands which are present in poky/scripts.

The script also export bitbake* commands from poky/bitbake/bin.

The line responsible for that is in:

• poky/scripts/oe-buildenv-internal (line 99):

# Make sure our paths are at the beginning of $PATH
for newpath in "$BITBAKEDIR/bin" "$OEROOT/scripts"; do
    # Remove any existences of $newpath from $PATH
    PATH=$(echo $PATH | sed -re "s#(^|:)$newpath(:|$)#\2#g;s#^:##")

    # Add $newpath to $PATH
    PATH="$newpath:$PATH"
done

So, always if you open new terminal:

source /yocto/source/poky/oe-init-build-env /yoctu/build

EDIT

If you already have a build folder, make sure to provide the right path for that folder to the oe-init-build-env script.

If you provide new path to non-existing folder, than the script will create another build for you.

EDIT2

To source poky environment according to your path:

• Relative:

cd ~/Documents/yocto/source/poky
source oe-init-build-env build
                           ^
                           |
(because build is in same folder as the script)

• Absolute:

source /home/$USER/Documents/yocto/source/poky/oe-init-build-env /home/$USER/Documents/yocto/source/poky/build 

THE RULE

source <path/to/oe-init-build-env> <path/to/build/folder>

If <path/to/build/folder> exists then, poky will source the existing build environment.

If <path/to/build/folder> does not exist, poky will create new build under the same name and path.

Answered By - Talel BELHADJSALEM