From 4d089e8d0133db08d18f6d2589f9ec24dd117391 Mon Sep 17 00:00:00 2001
From: pat-s <patrick.schratz@gmail.com>
Date: Sat, 6 Dec 2025 15:47:59 +0100
Subject: [PATCH] chore: fix alpine3.22+ builds with R <= 4.4.0

---
 builder/build.sh           | 13 +++++++++++++
 builder/docker-compose.yml |  1 +
 2 files changed, 14 insertions(+)

diff --git a/builder/build.sh b/builder/build.sh
index 549e461..427da6e 100755
--- a/builder/build.sh
+++ b/builder/build.sh
@@ -110,6 +110,19 @@ compile_r() {
     echo "Setting FFLAGS: ${FFLAGS}"
   fi
 
+  # R 4.3.x and below have K&R style XDR code that fails with GCC 14+
+  # GCC 14 treats () in prototypes as "zero args" instead of "unspecified args"
+  # Using -std=gnu17 restores the old behavior where () means unspecified args
+  # Fixed in R 4.4.0: https://bugs.r-project.org/show_bug.cgi?id=18755
+  echo "DEBUG: r_version=${r_version}, gcc_major_version=${gcc_major_version}"
+  echo "DEBUG: Checking if ${r_version} < 4.4.0 AND ${gcc_major_version} > 13"
+  if _version_is_less_than "${r_version}" 4.4.0 && _version_is_greater_than "${gcc_major_version}" 13; then
+    export CFLAGS="${CFLAGS:--g -O2} -std=gnu17"
+    echo "Setting CFLAGS for GCC 14+ compatibility: ${CFLAGS}"
+  else
+    echo "DEBUG: Condition not met, skipping GCC 14 workaround"
+  fi
+
   # Avoid a PCRE2 dependency for R 3.5 and 3.6. R 3.x uses PCRE1, but R 3.5+
   # will link against PCRE2 if present, although it is not actually used.
   # Since there's no way to disable this in the configure script, and we need
diff --git a/builder/docker-compose.yml b/builder/docker-compose.yml
index 8e06b87..63094ea 100644
--- a/builder/docker-compose.yml
+++ b/builder/docker-compose.yml
@@ -83,6 +83,7 @@ services:
     image: r-builds:alpine-323
     volumes:
       - /tmp/alpine-323:/tmp/output/alpine-323
+      - ./build.sh:/build.sh:ro
   debian-10:
     command: ./build.sh
     environment: