fix(gawk): add typed read_func prototype patch and validate with dry-run AND

fix(import-payload): switch to procfs /proc/partitions major/minor enumeration with magic-verified payload import

steps-guix/gawk-4.2.1/patches/fix-read-func-prototype.patch

@@ -0,0 +1,53 @@
+SPDX-License-Identifier: GPL-3.0-or-later
+
+Fix read_func prototype to use a modern typed function pointer.
+
+--- gawk-4.2.1/gawkapi.h
++++ gawk-4.2.1/gawkapi.h
+@@ -190,7 +190,7 @@
+ 	 * No argument prototype on read_func to allow for older systems
+ 	 * whose headers are not up to date.
+ 	 */
+-	ssize_t (*read_func)();
++	ssize_t (*read_func)(int, void *, size_t);
+ 
+ 	/*
+ 	 * The close_func is called to allow the parser to free private data.
+--- gawk-4.2.1/io.c
++++ gawk-4.2.1/io.c
+@@ -310,7 +310,7 @@
+ 
+ static NODE *in_PROCINFO(const char *pidx1, const char *pidx2, NODE **full_idx);
+ static long get_read_timeout(IOBUF *iop);
+-static ssize_t read_with_timeout(int fd, char *buf, size_t size);
++static ssize_t read_with_timeout(int fd, void *buf, size_t size);
+ 
+ static bool read_can_timeout = false;
+ static long read_timeout;
+@@ -3340,7 +3340,7 @@
+ 
+ 	iop->public.fd = fd;
+ 	iop->public.name = name;
+-	iop->public.read_func = ( ssize_t(*)() ) read;
++	iop->public.read_func = (ssize_t (*)(int, void *, size_t)) read;
+ 	iop->valid = false;
+ 	iop->errcode = errno_val;
+ 
+@@ -4318,7 +4318,7 @@
+ 		tmout = read_default_timeout;	/* initialized from env. variable in init_io() */
+ 
+ 	/* overwrite read routine only if an extension has not done so */
+-	if ((iop->public.read_func == ( ssize_t(*)() ) read) && tmout > 0)
++	if ((iop->public.read_func == (ssize_t (*)(int, void *, size_t)) read) && tmout > 0)
+ 		iop->public.read_func = read_with_timeout;
+ 
+ 	return tmout;
+@@ -4330,7 +4330,7 @@
+  */
+ 
+ static ssize_t
+-read_with_timeout(int fd, char *buf, size_t size)
++read_with_timeout(int fd, void *buf, size_t size)
+ {
+ #if ! defined(VMS)
+ 	fd_set readfds;

steps/improve/import_payload.sh

@@ -8,8 +8,11 @@ set -ex
 if [ "${PAYLOAD_REQUIRED}" = True ]; then
     mkdir -p /external/distfiles
     mkdir -p /proc
-    mount -t proc proc /proc >/dev/null 2>&1 || :
 
+    # Reliable enumeration in Fiwix: mount procfs and read /proc/partitions.
+    if [ ! -r /proc/partitions ]; then
+        mount -t proc proc /proc
+    fi
     if [ ! -r /proc/partitions ]; then
         echo "payload-import failed: /proc/partitions is unavailable." >&2
         exit 1
@@ -22,13 +25,13 @@ if [ "${PAYLOAD_REQUIRED}" = True ]; then
                 continue
                 ;;
             *[0-9])
-                # Skip partitions (sda1, vdb2, ...); payload is attached as a whole disk.
+                # Skip partitions (hda1, sdb2, ...); payload is a whole disk.
                 continue
                 ;;
         esac
 
         dev_path="/dev/${name}"
-        mknod -m 600 "${dev_path}" b "${major}" "${minor}" >/dev/null 2>&1 || :
+        [ -b "${dev_path}" ] || mknod -m 600 "${dev_path}" b "${major}" "${minor}"
 
         if payload-import --probe "${dev_path}"; then
             payload-import --device "${dev_path}" /external/distfiles
@@ -38,7 +41,7 @@ if [ "${PAYLOAD_REQUIRED}" = True ]; then
     done < /proc/partitions
 
     if [ "${found_payload}" != 1 ]; then
-        echo "payload-import failed: no payload image found on probed block devices." >&2
+        echo "payload-import failed: no payload image found in /proc/partitions." >&2
         exit 1
     fi
 fi

steps/payload-import-1.0/src/payload-import.c

@@ -227,10 +227,10 @@ static int extract_payload(const char *device, const char *dest_dir)
 
 static int import_from_first_payload(const char *dest_dir)
 {
-	const char *prefixes[] = {"/dev/sd", "/dev/vd", "/dev/hd"};
+	const char *prefixes[] = {"/dev/sd", "/dev/hd", "/dev/vd", "/dev/xvd"};
 	int p;
 
-	for (p = 0; p < 3; ++p) {
+	for (p = 0; p < 4; ++p) {
 		char letter;
 		for (letter = 'b'; letter <= 'z'; ++letter) {
 			char device[16];