From 537a3e43fea2e7986e4b3afd96d881587ae6b93c Mon Sep 17 00:00:00 2001
From: Geoff Bourne <itzgeoff@gmail.com>
Date: Fri, 17 Jul 2026 07:54:30 -0500
Subject: [PATCH] Use gcompat to ensure mc-image-helper runs on aarch64+alpine
 (#4176)

---
 .github/workflows/build.yml      | 16 ++--------------
 Dockerfile                       |  2 +-
 build/alpine/install-packages.sh |  1 +
 scripts/start-configuration      |  4 ++++
 4 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e26406d5..a16732be 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -45,12 +45,12 @@ jobs:
             baseImage: eclipse-temurin:25-jre-noble
             platforms: linux/amd64,linux/arm64,linux/riscv64
             mcVersion: latest
+            # forked build that include riscv64
+            knockdRepoOrg: Opvolger/knock
           - variant: java25-alpine
             baseImage: eclipse-temurin:25-jre-alpine
             platforms: linux/amd64,linux/arm64
             mcVersion: latest
-            # For GLIBC_2.34 support (and Alpine)
-            knockdRepoOrg: Metalcape/knock
           - variant: java25-jdk
             baseImage: eclipse-temurin:25
             platforms: linux/amd64,linux/arm64
@@ -68,23 +68,17 @@ jobs:
             baseImage: eclipse-temurin:21-jre-alpine
             platforms: linux/amd64,linux/arm64
             mcVersion: 1.21.11
-            # For GLIBC_2.34 support (and Alpine)
-            knockdRepoOrg: Metalcape/knock
         # JAVA 17:
           - variant: java17
             # jammy doesn't work until minecraft updates to https://github.com/netty/netty/issues/12343
             baseImage: eclipse-temurin:17-jre-focal
             platforms: linux/amd64,linux/arm/v7,linux/arm64
             mcVersion: 1.20.4
-            # For GLIBC_2.34 support (and Alpine)
-            knockdRepoOrg: Metalcape/knock
         # JAVA 16
           - variant: java16
             baseImage: adoptopenjdk:16-jre-hotspot
             platforms: linux/amd64,linux/arm/v7,linux/arm64
             mcVersion: 1.16.5
-            # For GLIBC_2.34 support
-            knockdRepoOrg: Metalcape/knock
             # Pin version for pre-Java 17
             mcHelperVersion: 1.51.3-java8
         # JAVA 11
@@ -92,8 +86,6 @@ jobs:
             baseImage: adoptopenjdk:11-jre-hotspot
             platforms: linux/amd64,linux/arm/v7,linux/arm64
             mcVersion: 1.16.4
-            # For GLIBC_2.34 support
-            knockdRepoOrg: Metalcape/knock
             # Pin version for pre-Java 17
             mcHelperVersion: 1.51.3-java8
         # JAVA 8: NOTE: Unable to go past 8u312 because of Forge dependencies
@@ -101,16 +93,12 @@ jobs:
             baseImage: eclipse-temurin:8u312-b07-jre-focal
             platforms: linux/amd64,linux/arm/v7,linux/arm64
             mcVersion: 1.12.2
-            # For GLIBC_2.34 support
-            knockdRepoOrg: Metalcape/knock
             # Pin version for Java 8, also be sure to set in verify-pr.yml
             mcHelperVersion: 1.51.3-java8
           - variant: java8-jdk
             baseImage: eclipse-temurin:8u312-b07-jdk-focal
             platforms: linux/amd64,linux/arm64
             mcVersion: 1.12.2
-            # For GLIBC_2.34 support
-            knockdRepoOrg: Metalcape/knock
             # Pin version for Java 8, also be sure to set in verify-pr.yml
             mcHelperVersion: 1.51.3-java8
     env:
diff --git a/Dockerfile b/Dockerfile
index b71a524c..c8a140ac 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,7 +13,7 @@ ARG EXTRA_DNF_PACKAGES=""
 ARG EXTRA_ALPINE_PACKAGES=""
 ARG FORCE_INSTALL_PACKAGES=1
 ARG KNOCKD_VERSION=0.8.1
-ARG KNOCKD_REPO_ORG=Opvolger/knock
+ARG KNOCKD_REPO_ORG=Metalcape/knock
 RUN --mount=target=/build,source=build \
     TARGET=${TARGETARCH}${TARGETVARIANT} \
     /build/run.sh install-packages
diff --git a/build/alpine/install-packages.sh b/build/alpine/install-packages.sh
index daf91da2..633bdc1c 100755
--- a/build/alpine/install-packages.sh
+++ b/build/alpine/install-packages.sh
@@ -35,6 +35,7 @@ apk add --no-cache -U \
     libcap \
     numactl \
     jattach \
+    gcompat \
     ${EXTRA_ALPINE_PACKAGES}
 
 # Download and install patched knockd
diff --git a/scripts/start-configuration b/scripts/start-configuration
index cd798ee4..90b30d61 100755
--- a/scripts/start-configuration
+++ b/scripts/start-configuration
@@ -33,6 +33,10 @@ if (( $(mc-image-helper java-release) >= 17 )); then
   export MC_IMAGE_HELPER_OPTS
 fi
 
+if [[ $(getDistro) == alpine ]]; then
+  export LD_PRELOAD=/lib/libgcompat.so.0
+fi
+
 export HOME=/data
 
 log "Running as uid=$(id -u) gid=$(id -g) with /data as '$(ls -lnd /data)'"