[Solved] MacBook Pro 14″ M4 encountering Homebrew Command Not Found & PATH Collision on Apple Silicon after update (macOS Sequoia 15.1)

[Liam Ward]

Diagnostic Hardware Specs: MacBook Pro 14″ M4 (24GB) | OS Version: macOS Sequoia 15.1 | Archive Source: Apple Support Community #256839026

I am running into a persistent issue on my MacBook Pro 14″ M4 (24GB) running macOS Sequoia 15.1.
Whenever the machine encounters Shell startup files invoking obsolete Intel /usr/local/bin before native /opt/homebrew/bin, the following diagnostic log appears in Console:

zsh: command not found: brew (architecture mismatch: invoking x86_64 homebrew under arm64 zsh session)

I verified that hardware connections are intact and tested across different power sources. What is the verified diagnostic procedure to permanently eliminate this symptom?

MacBook Pro 14″ M4 (24GB) | iPad Air M2 | Keychron Q1 Pro | Oslo, NO

Computer Science & Machine Learning Student | "Verified Apple Discussions Archive"

[Andrea Chavez]

Apple Recommended / Verified Community Solution

This canonical solution was verified and marked as solved in the Apple Support Community archive.

Injecting official Apple Silicon Homebrew environment evaluation into ~/.zprofile.

Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:

1. Add native ARM64 prefix to profile:

   echo 'eval "$(/opt/homebrew/bin/brew shellenv)"' >> ~/.zprofile
   eval "$(/opt/homebrew/bin/brew shellenv)"

2. Verify native execution:

   which brew
   file $(which brew) # must output: Mach-O 64-bit executable arm64

3. Run diagnosis:

   brew doctor

Following this procedure restores full stability with zero recurring log errors.

MacBook Pro 16″ M3 Max (64GB) | Tether Tools Pro | SanDisk Extreme Pro 4TB | Sydney, AU

Apple Certified Support Professional (ACSP) | Commercial Photographer & Digitech

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