Linux Execution Guide (Permission Denied)
=========================================

If you encounter a ``Permission denied`` error (error 13) when attempting to run Blender from the IDE, particularly when using a downloaded version on a separate partition (like ``/mnt/data``), the cause is likely a filesystem-level restriction rather than simple file permissions.

Symptoms
--------

When starting a Run Configuration or detecting Python info, the IDE reports:

.. code-block:: text

   Cannot run program ".../blender" (in directory "..."): error=13, Permission denied

Even if you run ``chmod +x`` on the binary, the error persists.

Root Cause: The ``noexec`` Flag
-------------------------------

On Linux, filesystems can be mounted with the ``noexec`` flag, which prevents any binary from being executed directly from that partition. This is a common security feature.

A frequent cause of this is the ``users`` (or ``user``) option in your ``/etc/fstab`` file. On many Linux distributions, the ``users`` flag **automatically implies** several restrictive flags:
*   ``noexec``: No programs can be executed.
*   ``nosuid``: Set-user-identifier bits are ignored.
*   ``nodev``: Device files are not interpreted.

Verification
------------

To confirm if your partition has the ``noexec`` flag, run:

.. code-block:: bash

   mount | grep "/mnt/data"

Look for ``noexec`` in the parentheses. Alternatively, check your mount configuration:

.. code-block:: bash

   cat /etc/fstab | grep "/mnt/data"

If you see ``users`` without an explicit ``exec``, then ``noexec`` is active.

Solutions
---------

Option 1: Update /etc/fstab (Permanent Fix)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Modify your mount options to explicitly allow execution by adding the ``exec`` flag after ``users``. NOTE: nvim, micro, vim, or any other TUI text editor can be used in place of Nano

1. Open ``/etc/fstab`` as root:

   .. code-block:: bash

      sudo nano /etc/fstab

2. Locate the line for your partition and change ``users`` to ``users,exec``:

   .. code-block:: text

      UUID=...  /mnt/data  btrfs  nofail,users,exec  0 0

3. Save the file and remount the drive:

   .. code-block:: bash

      sudo mount -o remount /mnt/data

4. **Restart the IDE** to ensure it picks up the updated mount state.

Option 2: Use the Home Partition
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If you cannot or do not want to change mount options, move the Blender downloads to your home directory (usually on the ``/`` partition), which typically allows execution.

1. Go to **Settings/Preferences** > **Blender Extensions**.
2. Change the **Downloads Path** to a directory within ``/home/your-user/``.

Option 3: Manual Remount (Temporary, NOT recommended)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You can temporarily allow execution until the next reboot:

.. code-block:: bash

   sudo mount -o remount,exec /mnt/data