nixos-anywhere-pxe: explicitly print nixos-anywhere cmd including the ssh key

this allows the user to just copy paste the command and run it manually, in case it failed

Author: pogobanane

src/nixos_anywhere_pxe/__init__.py

@@ -346,22 +346,25 @@ def nixos_anywhere(
     ssh_private_key: Path,
     nixos_anywhere_args: list[str],
 ) -> None:
+    cmd = [
+        # FIXME: path
+        "bash",
+        str(NIXOS_ANYWHERE_SH),
+        "--flake",
+        flake,
+        "-L",
+        # do not substitute because we do not have internet and copying locally is faster.
+        "--no-substitute-on-destination",
+        ip,
+        *nixos_anywhere_args,
+    ]
     run(
-        [
-            # FIXME: path
-            "bash",
-            str(NIXOS_ANYWHERE_SH),
-            "--flake",
-            flake,
-            "-L",
-            # do not substitute because we do not have internet and copying locally is faster.
-            "--no-substitute-on-destination",
-            ip,
-        ]
-        + nixos_anywhere_args,
+        cmd,
         extra_env=dict(SSH_PRIVATE_KEY=ssh_private_key.read_text()),
         check=False,
     )
+    print("If the installation failed, you may run the install command manually again:")
+    print(f"{cmd} -i {ssh_private_key.read_text()}")
 
 
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