add fallback if a user has no home

this is useful for testing and more robust

Author: Mic92

src/nixos-anywhere.sh

@@ -465,7 +465,14 @@ runVmTest() {
 
 uploadSshKey() {
   # ssh-copy-id requires this directory
-  mkdir -p "$HOME/.ssh/"
+  local sshCopyHome="$HOME"
+  if ! mkdir -p "$HOME/.ssh/" 2>/dev/null; then
+    # Fallback: create a temporary home directory for ssh-copy-id in sshKeyDir
+    sshCopyHome="$sshKeyDir/ssh-home"
+    mkdir -p "$sshCopyHome/.ssh"
+    echo "Warning: Could not create $HOME/.ssh, using temporary directory: $sshCopyHome"
+  fi
+  
   if [[ -n ${sshPrivateKeyFile} ]]; then
     cp "$sshPrivateKeyFile" "$sshKeyDir/nixos-anywhere"
     ssh-keygen -y -f "$sshKeyDir/nixos-anywhere" >"$sshKeyDir/nixos-anywhere.pub"
@@ -477,7 +484,7 @@ uploadSshKey() {
   step Uploading install SSH keys
   until
     if [[ ${envPassword} == y ]]; then
-      sshpass -e \
+      HOME="$sshCopyHome" sshpass -e \
         ssh-copy-id \
         -o ConnectTimeout=10 \
         "${sshArgs[@]}" \
@@ -486,7 +493,7 @@ uploadSshKey() {
       # To override `IdentitiesOnly=yes` set in `sshArgs` we need to set
       # `IdentitiesOnly=no` first as the first time an SSH option is
       # specified on the command line takes precedence
-      ssh-copy-id \
+      HOME="$sshCopyHome" ssh-copy-id \
         -o IdentitiesOnly=no \
         -o ConnectTimeout=10 \
         "${sshArgs[@]}" \

tests/ubuntu-kexec-test.nix

@@ -0,0 +1,76 @@
+{ pkgs, nixos-anywhere, kexec-installer, nix-vm-test, ... }:
+
+let
+  # Create dummy store paths for testing
+  testPaths = pkgs.runCommand "test-store-paths" {} ''
+    mkdir -p $out
+    echo "echo 'Dummy disko script'" > $out/disko
+    echo "echo 'Dummy system closure'" > $out/system
+    chmod +x $out/disko $out/system
+  '';
+in
+nix-vm-test.ubuntu."22_04" {
+  memorySize = 2048;
+
+  # Forward SSH port to allow connection from the host
+  virtualisation.forwardPorts = [
+    { from = "host"; host.port = 2222; guest.port = 22; }
+  ];
+
+  # Make the SSH keys available in the VM
+  sharedDirs = {
+    sshKeys = {
+      source = "${nixos-anywhere}/tests/modules/ssh-keys";
+      target = "/tmp/ssh-keys";
+    };
+  };
+
+  # The test script
+  testScript = ''
+    # Wait for the system to be fully booted
+    vm.wait_for_unit("multi-user.target")
+
+    # Unmask SSH service (which is masked by default in the test VM)
+    vm.succeed("systemctl unmask ssh.service")
+    vm.succeed("systemctl unmask ssh.socket")
+    vm.succeed("systemctl start ssh")
+
+    # Setup SSH with the existing keys
+    vm.succeed("mkdir -p /root/.ssh")
+    vm.succeed("cp /tmp/ssh-keys/ssh.pub /root/.ssh/authorized_keys")
+    vm.succeed("chmod 644 /root/.ssh/authorized_keys")
+
+    # Setup SSH for connection from host
+    vm.succeed("sed -i 's/#PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config")
+    vm.succeed("systemctl restart ssh")
+    
+    # Wait for SSH to be available
+    vm.wait_for_open_port(22)
+    print("SSH server is ready")
+
+    # Run nixos-anywhere from the host against the VM
+    print("Starting kexec test phase...")
+    
+    # Use Python's subprocess to run nixos-anywhere from the host
+    import subprocess
+    
+    cmd = f"""${nixos-anywhere}/bin/nixos-anywhere \\
+      -i ${nixos-anywhere}/tests/modules/ssh-keys/ssh \\
+      --ssh-port 2222 \\
+      --phases kexec \\
+      --kexec ${kexec-installer} \\
+      --store-paths ${testPaths}/disko ${testPaths}/system \\
+      --debug \\
+      root@localhost
+    """
+    
+    print(f"Running command: {cmd}")
+    result = subprocess.run(cmd, shell=True, check=False)
+    
+    if result.returncode == 0:
+      print("kexec phase completed successfully")
+    else:
+      print(f"nixos-anywhere failed with exit code {result.returncode}")
+      raise Exception("nixos-anywhere command failed")
+  '';
+}