Re: Build issue with postgresql 17 undefined reference to `pg_encoding_to_char' and `pg_char_to_encoding'

# syntax=docker/dockerfile:1
FROM chainguard/git:latest-dev AS builder
USER root
WORKDIR /app
RUN apk update && apk add --no-cache --update-cache \
    clang-19 \
    bison \
    curl \
    flex \
    make \
    perl

ARG PG=17.0
RUN curl -L https://ftp.postgresql.org/pub/source/v$PG/postgresql-$PG.tar.bz2 | tar -xj
COPY <<EOF ./pg.patch
Subject: [PATCH] Fix static build
---
Index: src/bin/initdb/Makefile
<+>UTF-8
===================================================================
diff --git a/src/bin/initdb/Makefile b/src/bin/initdb/Makefile
--- a/src/bin/initdb/Makefile (revision c4b8a916f8a53379621825028532b038e004f891)
+++ b/src/bin/initdb/Makefile (date 1728466911177)
@@ -20,7 +20,8 @@
 # from libpq, else we have risks of version skew if we run with a libpq
 # shared library from a different PG version.  Define
 # USE_PRIVATE_ENCODING_FUNCS to ensure that that happens.
-override CPPFLAGS := -DUSE_PRIVATE_ENCODING_FUNCS -I$(libpq_srcdir) -I$(top_srcdir)/src/timezone $(ICU_CFLAGS) $(CPPFLAGS)
+#override CPPFLAGS := -DUSE_PRIVATE_ENCODING_FUNCS -I$(libpq_srcdir) -I$(top_srcdir)/src/timezone $(ICU_CFLAGS) $(CPPFLAGS)
+override CPPFLAGS := -I$(libpq_srcdir) -I$(top_srcdir)/src/timezone $(ICU_CFLAGS) $(CPPFLAGS)

 # We need libpq only because fe_utils does.
 LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(ICU_LIBS)
Index: src/common/Makefile
<+>UTF-8
===================================================================
diff --git a/src/common/Makefile b/src/common/Makefile
--- a/src/common/Makefile (revision c4b8a916f8a53379621825028532b038e004f891)
+++ b/src/common/Makefile (date 1728466354406)
@@ -143,7 +143,7 @@
 # Files in libpgcommon.a should use/export the "xxx_private" versions
 # of pg_char_to_encoding() and friends.
 #
-$(OBJS_FRONTEND): CPPFLAGS += -DUSE_PRIVATE_ENCODING_FUNCS
+#$(OBJS_FRONTEND): CPPFLAGS += -DUSE_PRIVATE_ENCODING_FUNCS


 #
EOF
RUN cd postgresql-$PG && \
    git apply ../pg.patch && \
    export CC=clang CXX=clang++ && \
    ./configure --without-openssl --without-icu --without-ldap --without-readline --without-zlib --without-tcl --without-python --prefix=/usr/local && \
    cd src && for lib in include common port interfaces/libpq ; do cd $lib && make && make install && cd - ; done

COPY <<EOF ./main.cpp
#include<libpq-fe.h>
int main(){return PQconnectdb("")==NULL;}
EOF

RUN clang++ -static -o main main.cpp -lpq -lpgcommon -lpgport
ENTRYPOINT ["./main"]
CMD []