Consolidate Intel-macOS instructions into building-from-source

Author: keyprocedure

docs/source/using-executorch-building-from-source.md

@@ -65,13 +65,19 @@ Or alternatively, [install conda on your machine](https://conda.io/projects/cond
    ./install_executorch.sh
    ```
 
-  Use the [`--use-pt-pinned-commit` flag](https://github.com/pytorch/executorch/blob/main/install_executorch.sh) to install Executorch with an existing PyTorch build.  
-  See the [PyTorch instructions](https://github.com/pytorch/pytorch#installation) on how to build PyTorch from source.
+  See the [PyTorch instructions](https://github.com/pytorch/pytorch#installation) on how to build PyTorch from source.  
+
+  Use the [`--use-pt-pinned-commit` flag](../../install_executorch.py) to install ExecuTorch with an existing PyTorch build:
 
    ```bash
    ./install_executorch.sh --use-pt-pinned-commit
    ```
 
+  For Intel-based macOS systems, use the [`--use-pt-pinned-commit --minimal` flags](../../install_executorch.py):
+  ```bash
+  ./install_executorch.sh --use-pt-pinned-commit --minimal
+  ```
+
    Not all backends are built into the pip wheel by default. You can link these missing/experimental backends by turning on the corresponding cmake flag. For example, to include the MPS backend:
 
   ```bash

docs/source/using-executorch-ios.md

@@ -114,13 +114,6 @@ python3 -m venv .venv && source .venv/bin/activate && pip install --upgrade pip
 ./backends/apple/coreml/scripts/install_requirements.sh
 ```
 
-- **Intel-based macOS** systems require building PyTorch, Torchvision, and Torchaudio from source:  
-  - Use the [`--use-pt-pinned-commit --minimal` flags](https://github.com/pytorch/executorch/blob/main/install_executorch.py) to install Executorch with an existing PyTorch build.  
-    See the [PyTorch instructions](https://github.com/pytorch/pytorch#installation) on how to build PyTorch from source.
-    ```bash
-    ./install_executorch.sh --use-pt-pinned-commit --minimal
-    ```
-
 5. Install [CMake](https://cmake.org):
 
 Download the macOS binary distribution from the [CMake website](https://cmake.org/download), open the `.dmg` file, move `CMake.app` to the `/Applications` directory, and then run the following command to install the CMake command-line tools:

install_requirements.py

@@ -175,7 +175,7 @@ def install_optional_example_requirements(use_pytorch_nightly):
 # Prebuilt binaries for Intel-based macOS are no longer available on PyPI; users must compile from source.
 # PyTorch stopped building macOS x86_64 binaries since version 2.3.0 (January 2024).
 def is_intel_mac_os():
-    # Returns True if running on Intel macOS
+    # Returns True if running on Intel macOS.
     return platform.system().lower() == "darwin" and platform.machine().lower() in (
         "x86",
         "x86_64",