opencode-bigsur

Run opencode (the official Bun-compiled opencode-ai binary) on macOS 11 Big Sur.

The stock binary targets minos 13.0, so it refuses to launch on Big Sur. Two things break once you get it loading:

1. ICU. The binary links /usr/lib/libicucore.A.dylib. Big Sur ships ICU 66, which is missing 11 symbols the binary needs (ubrk_clone, the unumrf_* range formatters, udtitvfmt_formatCalendarToResult, uplrules_selectForRange, ucal_getTimeZoneOffsetFromLocal).
2. SQLite. opencode's SQL uses RETURNING (SQLite >= 3.35) and jsonb (>= 3.45). Big Sur's system SQLite is 3.32, so session creation fails with SQLiteError: near "returning": syntax error. Bun dlopens libsqlite3.dylib by leaf name, so a newer copy on the dyld fallback path wins.

This repo builds a small ICU shim and a modern SQLite dylib, rewrites the binary to use them, and installs everything for the current user.

Verified on: macOS 11.7.10, MacBookAir6,2 (dual-core i5, 8 GB), opencode 1.19.3 (--version, models, chat, and tool calls all pass).

Files

• build.sh – builds libicu.dylib (re-exports the SDK's ICU + defines the 11 missing symbols) and patches/re-signs the opencode binary.
• build-sqlite.sh – downloads and compiles a modern libsqlite3.dylib.
• install.sh – installs the built artifacts for the current user.
• ubrk_shim.c – the ICU compatibility shim source.

Usage

Run the build on a Mac with an Xcode/CLT macOS 11 SDK (a newer Mac is fine; the target machine does not need a compiler):

# 1. get the raw darwin-x64 binary (postinstall won't run it, which is good,
#    since it can't execute on a pre-13 machine either)
npm pack opencode-darwin-x64@1.19.3
tar xzf opencode-darwin-x64-1.19.3.tgz

# 2. build (pass the raw binary; default is your global opencode-ai install)
./build.sh package/bin/opencode
./build-sqlite.sh

Copy dist/ to the Big Sur machine and install:

./install.sh          # on the Big Sur Mac; writes to ~/opencode and ~/lib

Then open a new Terminal and run opencode.

If the SDK isn't at the default path, override it:

SDK=/path/to/MacOSX11.sdk ./build.sh /path/to/opencode

Caveats

• Do not run opencode upgrade on the Big Sur build. It replaces the patched binary with the official minos 13 build, which will not launch. To update, re-run build.sh against the new opencode-darwin-x64 package.
• The install.sh PATH line is added to ~/.zshrc.
• This targets the terminal TUI. The Electron desktop app will not run on Big Sur (same minos floor, and it would be very slow on 2013-2014 Intel Macs anyway).