We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
`terraform_deployment` cannot load vars files if the root `terraform_module` is not in the same dir
**Describe the bug**

root/BUILD:
```
terraform_deployment(root_module="//mod0:mod0", var_files=["a.tfvars"])
```
root/a.tfvars:
```
var0 = "hihello"
```
mod/BUILD:
```
terraform_module()
```
mod/main.tf:
```
resource "null_resource" "dep" {}
```

running `pants experimental-deploy //root:root` yields:
```
Engine traceback:
  in select
    ..
  in pants.core.goals.deploy.run_deploy
    `experimental-deploy` goal

Traceback (most recent call last):
  File "/home/lilatomic/vnd/pants/src/python/pants/core/goals/deploy.py", line 176, in run_deploy
    deploy_processes = await MultiGet(
  File "/home/lilatomic/vnd/pants/src/python/pants/engine/internals/selectors.py", line 374, in MultiGet
    return await _MultiGet(tuple(__arg0))
  File "/home/lilatomic/vnd/pants/src/python/pants/engine/internals/selectors.py", line 172, in __await__
    result = yield self.gets
ValueError: 'root/a.tfvars' is not in the subpath of 'mod0' OR one path is relative and the other is absolute.
```

**Pants version**
2.18+


--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `src/python/pants/backend/terraform/utils.py`
Content:
```
1 # Copyright 2023 Pants project contributors (see CONTRIBUTORS.md).
2 # Licensed under the Apache License, Version 2.0 (see LICENSE).
3 import shlex
4 from pathlib import PurePath
5 
6 
7 def terraform_arg(name: str, value: str) -> str:
8     """Format a Terraform arg."""
9     return f"{name}={shlex.quote(value)}"
10 
11 
12 def terraform_relpath(chdir: str, target: str) -> str:
13     """Compute the relative path of a target file to the Terraform deployment root."""
14     return PurePath(target).relative_to(chdir).as_posix()
15
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/src/python/pants/backend/terraform/utils.py b/src/python/pants/backend/terraform/utils.py
--- a/src/python/pants/backend/terraform/utils.py
+++ b/src/python/pants/backend/terraform/utils.py
@@ -1,7 +1,7 @@
 # Copyright 2023 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
+import os.path
 import shlex
-from pathlib import PurePath
 
 
 def terraform_arg(name: str, value: str) -> str:
@@ -11,4 +11,4 @@
 
 def terraform_relpath(chdir: str, target: str) -> str:
     """Compute the relative path of a target file to the Terraform deployment root."""
-    return PurePath(target).relative_to(chdir).as_posix()
+    return os.path.relpath(target, start=chdir)

{"golden_diff": "diff --git a/src/python/pants/backend/terraform/utils.py b/src/python/pants/backend/terraform/utils.py\n--- a/src/python/pants/backend/terraform/utils.py\n+++ b/src/python/pants/backend/terraform/utils.py\n@@ -1,7 +1,7 @@\n # Copyright 2023 Pants project contributors (see CONTRIBUTORS.md).\n # Licensed under the Apache License, Version 2.0 (see LICENSE).\n+import os.path\n import shlex\n-from pathlib import PurePath\n \n \n def terraform_arg(name: str, value: str) -> str:\n@@ -11,4 +11,4 @@\n \n def terraform_relpath(chdir: str, target: str) -> str:\n     \"\"\"Compute the relative path of a target file to the Terraform deployment root.\"\"\"\n-    return PurePath(target).relative_to(chdir).as_posix()\n+    return os.path.relpath(target, start=chdir)\n", "issue": "`terraform_deployment` cannot load vars files if the root `terraform_module` is not in the same dir\n**Describe the bug**\r\n\r\nroot/BUILD:\r\n```\r\nterraform_deployment(root_module=\"//mod0:mod0\", var_files=[\"a.tfvars\"])\r\n```\r\nroot/a.tfvars:\r\n```\r\nvar0 = \"hihello\"\r\n```\r\nmod/BUILD:\r\n```\r\nterraform_module()\r\n```\r\nmod/main.tf:\r\n```\r\nresource \"null_resource\" \"dep\" {}\r\n```\r\n\r\nrunning `pants experimental-deploy //root:root` yields:\r\n```\r\nEngine traceback:\r\n  in select\r\n    ..\r\n  in pants.core.goals.deploy.run_deploy\r\n    `experimental-deploy` goal\r\n\r\nTraceback (most recent call last):\r\n  File \"/home/lilatomic/vnd/pants/src/python/pants/core/goals/deploy.py\", line 176, in run_deploy\r\n    deploy_processes = await MultiGet(\r\n  File \"/home/lilatomic/vnd/pants/src/python/pants/engine/internals/selectors.py\", line 374, in MultiGet\r\n    return await _MultiGet(tuple(__arg0))\r\n  File \"/home/lilatomic/vnd/pants/src/python/pants/engine/internals/selectors.py\", line 172, in __await__\r\n    result = yield self.gets\r\nValueError: 'root/a.tfvars' is not in the subpath of 'mod0' OR one path is relative and the other is absolute.\r\n```\r\n\r\n**Pants version**\r\n2.18+\r\n\n", "before_files": [{"content": "# Copyright 2023 Pants project contributors (see CONTRIBUTORS.md).\n# Licensed under the Apache License, Version 2.0 (see LICENSE).\nimport shlex\nfrom pathlib import PurePath\n\n\ndef terraform_arg(name: str, value: str) -> str:\n    \"\"\"Format a Terraform arg.\"\"\"\n    return f\"{name}={shlex.quote(value)}\"\n\n\ndef terraform_relpath(chdir: str, target: str) -> str:\n    \"\"\"Compute the relative path of a target file to the Terraform deployment root.\"\"\"\n    return PurePath(target).relative_to(chdir).as_posix()\n", "path": "src/python/pants/backend/terraform/utils.py"}], "after_files": [{"content": "# Copyright 2023 Pants project contributors (see CONTRIBUTORS.md).\n# Licensed under the Apache License, Version 2.0 (see LICENSE).\nimport os.path\nimport shlex\n\n\ndef terraform_arg(name: str, value: str) -> str:\n    \"\"\"Format a Terraform arg.\"\"\"\n    return f\"{name}={shlex.quote(value)}\"\n\n\ndef terraform_relpath(chdir: str, target: str) -> str:\n    \"\"\"Compute the relative path of a target file to the Terraform deployment root.\"\"\"\n    return os.path.relpath(target, start=chdir)\n", "path": "src/python/pants/backend/terraform/utils.py"}]}