Update the Linux/macOS installation scripts.

Author: hameerabbasi

LAUNCH-SCRIPTS.md

@@ -13,48 +13,21 @@
 
 ### All of the scripts accept the following *optional* environment variables to customize their behavior:
 
-- `OT_CONDA_CMD`: Sets a custom Conda command or an absolute path to the binary (useful when it isn't in the user's `PATH`). If nothing is provided, we detect and use `CONDA_EXE` if available, which is a variable that's set by Conda itself and always points at the user's installed Conda binary.
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-- `OT_CONDA_ENV`: Sets the directory name (or an absolute/relative path) of the Conda environment. If a name or relative path is used, it will be relative to the OneTrainer directory. Defaults to `conda_env`.
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-- `OT_PYTHON_CMD`: Sets the Host's Python executable. It's used for creating the Python Venvs. This can be used to force the usage of a specific Python version's binary (such as `python3.10`) whenever the host has multiple versions installed. However, it's *always* recommended to use Conda or Pyenv instead, rather than relying on the host's unreliable system-wide Python binaries (which might change or be removed with system updates), so we don't recommend changing this option unless you *really* know what you're doing. Defaults to `python`.
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-- `OT_PYTHON_VENV`: Sets the directory name (or an absolute/relative path) of the Python Venv. If a name or relative path is used, it will be relative to the OneTrainer directory. Defaults to `venv`.
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-- `OT_PREFER_VENV`: If set to `true`, Conda will be ignored even if it exists on the system, and Python Venv will be used instead. This ensures that people who use `pyenv` (to choose which Python version to run on the host) can easily set up their desired Python Venv environments. Defaults to `false`.
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-- `OT_LAZY_UPDATES`: If set to `true`, OneTrainer's self-update process will only update the Python environment's dependencies if the OneTrainer source code has been modified since the previous dependency update. This speeds up executions of `update.sh`, and is generally safe, but may miss some updates and important bugfixes for external third-party dependencies. If you use this option, you must set it permanently for *every* script (not just `update.sh`). Defaults to `false`.
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 - `OT_CUDA_LOWMEM_MODE`: If set to `true`, it enables aggressive garbage collection in PyTorch to help with low-memory GPUs. Defaults to `false`.
 
-- `OT_PLATFORM_REQUIREMENTS`: Allows you to override which platform-specific "requirements" file you want to install. Defaults to `detect`, which automatically detects whether you have an AMD or NVIDIA GPU. But people with multi-GPU systems can use this setting to force a specific GPU acceleration framework's requirements. Valid values are `requirements-rocm.txt` for AMD, `requirements-cuda.txt` for NVIDIA, and `requirements-default.txt` for non-AMD/NVIDIA systems.
+- `OT_PLATFORM`: Allows you to override which platform you want to install for. Defaults to `detect`, which automatically detects whether you have an AMD or NVIDIA GPU, and falls back to CPU on failure. But people with multi-GPU systems can use this setting to force a specific GPU acceleration framework's requirements. Valid values are `rocm` for AMD, `cuda` for NVIDIA, and `default` for non-AMD/NVIDIA systems.
 
 - `OT_SCRIPT_DEBUG`: If set to `true`, it enables additional debug logging in the scripts. Defaults to `false`.
 
 
 ### Examples of how to use the custom environment variables:
 
-- You can provide custom environment variables directly on the command line, as follows: `env OT_PREFER_VENV="true" OT_CUDA_LOWMEM_MODE="true" OT_PLATFORM_REQUIREMENTS="requirements-cuda.txt" ./start-ui.sh`.
+- You can provide custom environment variables directly on the command line, as follows: `env OT_PLATFORM="rocm" OT_CUDA_LOWMEM_MODE="true" ./start-ui.sh`.
 - You can add them to your user's persistent environment variables, so that they are always active. The process varies depending on your operating system. On Linux, you can place them in `~/.config/environment.d/onetrainer.conf` (on all Systemd-based distros), which is a plaintext file with *one variable per line,* such as `OT_CUDA_LOWMEM_MODE="true"`. Beware that changes to `environment.d` requires a *complete system restart* to take effect (there is no command for reloading them live). To verify that your environment has been set persistently, you can then open a terminal window and run `printenv <variable name>` (such as `printenv OT_CUDA_LOWMEM_MODE`) to see if your custom values have taken effect.
 - If you're launching OneTrainer from your own, custom scripts, then you can instead `export` the new values (which tells the shell to pass those environment variables onto child processes). For example, by having a line such as `export OT_CUDA_LOWMEM_MODE="true"` before your script calls `./OneTrainer/start-ui.sh`.
 - If you're running OneTrainer inside a Docker/Podman container, you can instead use the [ENV](https://docs.docker.com/reference/dockerfile/#env) instruction in your `Dockerfile` / `Containerfile` to set the variables, such as `ENV OT_CUDA_LOWMEM_MODE="true"`.
 
 
-### Installing the required Python version for OneTrainer:
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-- If you've received a warning that your system's Python version is incorrect, then your system most likely doesn't have Conda installed, and has instead tried to create a Python Venv with your host's default Python version. If that version is incompatible with OneTrainer, then you'll have to resolve the problem by manually installing a compatible version. Alternatively, you are using an outdated Conda environment.
-- Begin by deleting the `venv` sub-directory inside the OneTrainer directory, to erase the invalid Python Venv (which was created with the wrong Python version). If you were using Conda, then you must instead delete the outdated `conda_env` sub-directory.
-- Now you'll have to choose which solution you prefer.
-- The most beginner-friendly solution is to install [Miniconda](https://docs.anaconda.com/miniconda/) on your system. OneTrainer will then automatically install and manage the correct Python version for you via Conda. You can stop reading here if you're choosing this solution. Everything will work automatically after that.
-- Alternatively, if you prefer a more lightweight and advanced solution, then you can use [pyenv](https://github.com/pyenv/pyenv), which allows you to set the exact Python version to use for OneTrainer's directory. If you're on Linux, then read their "[automatic installer](https://github.com/pyenv/pyenv?tab=readme-ov-file#automatic-installer)" section and follow the instructions. If you're on a Mac instead, then read their "[Homebrew](https://github.com/pyenv/pyenv?tab=readme-ov-file#homebrew-in-macos)" section (which is an open-source package manager for Macs).
-- After installing pyenv, you will also need to install the [Python build dependencies](https://github.com/pyenv/pyenv/wiki#suggested-build-environment) on your system, since pyenv installs each Python version by compiling them directly from the official source code.
-- Restart your shell, and then try the `pyenv doctor` command, which ensures that pyenv is loaded and verifies that your system contains all required dependencies for installing Python.
-- Run `pyenv install <python version>` to install whichever Python version is currently required by OneTrainer. You can look at the `OT_CONDA_USE_PYTHON_VERSION` variable at the top of the `lib.include.sh` file in OneTrainer's project directory, to see which Python version is recommended by OneTrainer at the moment.
-- Lastly, you must navigate to the OneTrainer directory, and then run `pyenv local <python version>` to force OneTrainer to use that version of Python. Your choice will be stored persistently in the hidden `.python-version` file, and can be changed again in the future by running the command again.
-- You can now run `python --version` to verify that the `python` command in OneTrainer is being mapped to the correct Python version by pyenv.
-- Everything is now ready for running OneTrainer!
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 ### Running custom script commands:
 
 - Always use `run-cmd.sh` when you want to execute any of OneTrainer's CLI tasks. It automatically validates the chosen target script's name, configures the runtime environment correctly, and then runs the target script with your given command-line arguments.