# GNAT toolchain now broken after OS upgrade to MacOS 26 (Tahoe), arm64

**URL:** https://forum.ada-lang.io/t/gnat-toolchain-now-broken-after-os-upgrade-to-macos-26-tahoe-arm64/3843
**Category:** General
**Created:** [September 19, 2025, 1:03am UTC](https://forum.ada-lang.io/t/gnat-toolchain-now-broken-after-os-upgrade-to-macos-26-tahoe-arm64/3843 "2025-09-19T01:03:36Z")
**Posts on this page:** 1
**Showing post:** 28

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### Author: ![tomekw](https://forum.ada-lang.io/user_avatar/forum.ada-lang.io/tomekw/32/883_2.png) [@tomekw](https://forum.ada-lang.io/u/tomekw)
#### Post date: [January 7, 2026, 2:42pm UTC](https://forum.ada-lang.io/t/gnat-toolchain-now-broken-after-os-upgrade-to-macos-26-tahoe-arm64/3843/28 "2026-01-07T14:42:20Z")

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Thanks!

For a reference, using a Fish shell, this solved the problem:

`set -gx SDKROOT “$(xcrun --sdk macosx --show-sdk-path)”`  
`set -gx LD_LIBRARY_PATH “$SDKROOT/usr/lib”`  
`set -gx LDFLAGS “-L$SDKROOT/usr/lib”`  
`set -gx LIBRARY_PATH “$SDKROOT/usr/lib”`

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