Improve the error message for installing tensorboardx (Lightning-AI#17053)

Author: awaelchli

src/lightning/fabric/CHANGELOG.md

@@ -76,6 +76,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 - Fixed issue where the wrapped dataloader `iter()` would be called twice ([#16841](https://github.com/Lightning-AI/lightning/pull/16841))
 
+- Improved the error message for installing tensorboard or tensorboardx ([#17053](https://github.com/Lightning-AI/lightning/pull/17053))
+
 
 ## [1.9.4] - 2023-03-01
 

src/lightning/fabric/loggers/tensorboard.py

@@ -91,7 +91,8 @@ def __init__(
  ):
  if not _TENSORBOARD_AVAILABLE and not _TENSORBOARDX_AVAILABLE:
  raise ModuleNotFoundError(
- "Neither `tensorboard` nor `tensorboardX` is available. Try `pip install`ing either."
+ "Neither `tensorboard` nor `tensorboardX` is available. Try `pip install`ing either.\n"
+ f"{str(_TENSORBOARDX_AVAILABLE)}\n{str(_TENSORBOARD_AVAILABLE)}"
  )
  super().__init__()
  root_dir = os.fspath(root_dir)

src/lightning/pytorch/CHANGELOG.md

@@ -439,6 +439,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Fixed an issue with comparing torch versions when using a version of torch built from source ([#17030](https://github.com/Lightning-AI/lightning/pull/17030))
 
 
+- Improved the error message for installing tensorboard or tensorboardx ([#17053](https://github.com/Lightning-AI/lightning/pull/17053))
+
+
 ## [1.9.4] - 2023-03-01
 
 ### Added

src/lightning/pytorch/loggers/tensorboard.py

@@ -117,7 +117,10 @@ def __init__(
  **kwargs,
  )
  if log_graph and not _TENSORBOARD_AVAILABLE:
- rank_zero_warn("You set `TensorBoardLogger(log_graph=True)` but `tensorboard` is not available.")
+ rank_zero_warn(
+ "You set `TensorBoardLogger(log_graph=True)` but `tensorboard` is not available.\n"
+ f"{str(_TENSORBOARD_AVAILABLE)}"
+ )
  self._log_graph = log_graph and _TENSORBOARD_AVAILABLE
  self.hparams: Union[Dict[str, Any], Namespace] = {}