SSH key loading error

### 1. **Check the Format of the SSH Key**
Ensure that the SSH private key is in the correct format. The key should be in the format:

-----BEGIN OPENSSH PRIVATE KEY-----
   <key data>
   -----END OPENSSH PRIVATE KEY-----

If your key is in PEM format (e.g., starts with `—–BEGIN RSA PRIVATE KEY—–`), you might need to convert it to the newer OpenSSH format.

You can convert an RSA private key to OpenSSH format with:

ssh-keygen -p -m PEM -f /path/to/your/private/key

### 2. **Ensure the Environment Variable is Set Correctly**
Check if the `$SSH_PRIVATE_KEY` environment variable is set correctly. You can print it out (excluding the private key data for security reasons) to verify that the key is being passed as expected:

echo "$SSH_PRIVATE_KEY" | head -n 5

This will print the first few lines of the key to check for any unwanted characters or formatting issues.

### 3. **Ensure No Extra Characters or Newlines**
The command `tr -d 'r'` is meant to remove any `r` characters (Windows-style line endings), but you might still have other hidden characters. You can try sanitizing the key further by using:

echo "$SSH_PRIVATE_KEY" | tr -d 'r' | sed 's/r//' | ssh-add -

Alternatively, you can pipe the key into a file and check it manually with a text editor to ensure no extra characters exist.

### 4. **Use a File Instead of Piping**
If the above steps don't resolve the issue, you can try saving the private key to a file first, then add it using `ssh-add`. This approach can help avoid issues with key formatting or variable interpolation. For example:

echo "$SSH_PRIVATE_KEY" > /tmp/temp_ssh_key
   chmod 600 /tmp/temp_ssh_key
   ssh-add /tmp/temp_ssh_key

This will save the private key to a temporary file and then add it using `ssh-add`.

### 5. **Check SSH and OpenSSL Versions**
Ensure that your system's `ssh` and `openssl` libraries are up-to-date, as older versions might cause compatibility issues with certain key formats. You can update the necessary packages by running:
– For Ubuntu/Debian:

sudo apt update
     sudo apt upgrade openssh-client openssl

– For RedHat/CentOS:

sudo yum update openssh openssl

After following these steps, try running the `ssh-add` command again, and it should resolve the error.