diff --git a/GCC-Install.sh b/GCC-Install.sh
index cd9f4400a..2e9d2f3ea 100755
--- a/GCC-Install.sh
+++ b/GCC-Install.sh
@@ -1,5 +1,59 @@
 # ApolloCrossDev Secondary Install Script v1.0
 
+set -e
+
+patch_amiga_gcc_sources() {
+    # Fix fd2sfd: 'false' is a reserved keyword in C23 (GCC 14+).
+    sed -i 's/typedef enum { false, nodef, real_error } Error;/typedef enum { no_error, nodef, real_error } Error;/' \
+        "$SOURCES/amiga-gcc/projects/fd2sfd/fd2inline.c"
+    sed -i 's/\bfalse\b/no_error/g' \
+        "$SOURCES/amiga-gcc/projects/fd2sfd/fd2inline.c"
+
+    # Fix readline signal handler prototypes for newer host compilers.
+    sed -E -i 's/^([[:space:]]*static[[:space:]]+RETSIGTYPE[[:space:]]+rl_signal_handler)[[:space:]]*\(\);/\1 (int);/' \
+        "$SOURCES/amiga-gcc/projects/binutils/readline/readline/signals.c"
+    sed -E -i 's/^([[:space:]]*static[[:space:]]+RETSIGTYPE[[:space:]]+rl_sigwinch_handler)[[:space:]]*\(\);/\1 (int);/' \
+        "$SOURCES/amiga-gcc/projects/binutils/readline/readline/signals.c"
+    sed -E -i 's/^typedef[[:space:]]+RETSIGTYPE[[:space:]]+SigHandler[[:space:]]*\(\);/typedef RETSIGTYPE SigHandler (int);/' \
+        "$SOURCES/amiga-gcc/projects/binutils/readline/readline/signals.c"
+    sed -E -i 's/^#  define SIGHANDLER_RETURN return \(0\)/#  define SIGHANDLER_RETURN return/' \
+        "$SOURCES/amiga-gcc/projects/binutils/readline/readline/signals.c"
+
+    # Work around GCC 15 ICE while compiling libstdc++ cxx11-shim_facets.
+    if ! grep -q "ApolloCrossDev workaround: avoid host GCC 15 ICE" "$SOURCES/amiga-gcc/projects/gcc/libstdc++-v3/src/c++11/cxx11-shim_facets.cc"; then
+        sed -i '/in code that uses the other std::string ABI from the replacing code\./a\
+// ApolloCrossDev workaround: avoid host GCC 15 ICE when compiling this TU.\
+#pragma GCC push_options\
+#pragma GCC optimize ("O0")' \
+            "$SOURCES/amiga-gcc/projects/gcc/libstdc++-v3/src/c++11/cxx11-shim_facets.cc"
+    fi
+}
+
+patch_timidity_sources() {
+    # Keep clean builds warning-free: align stream pointer type with call sites.
+    sed -i 's/static void compute_data(MidSong \*song, sint8 \*\*stream, sint32 count)/static void compute_data(MidSong *song, unsigned char **stream, sint32 count)/' \
+        "$SOURCES/timidity-source/playmidi.c"
+}
+
+patch_bgdbserver_sources() {
+    # Fix bgdbserver warnings with newer host compilers and Amiga varargs macros.
+    sed -i 's/void addBreakpoint(UWORD \* addr, short isTemp, UWORD \* restore);/void addBreakpoint(volatile UWORD * addr, short isTemp, volatile UWORD * restore);/' src/breakpoint.h
+    sed -i 's/void delBreakpoint(UWORD \* addr);/void delBreakpoint(volatile UWORD * addr);/' src/breakpoint.h
+    if ! grep -q "#include <stdlib.h>" src/breakpoint.c; then
+        sed -i '/#include "breakpoint.h"/a #include <stdlib.h>' src/breakpoint.c
+    fi
+    sed -i 's/UWORD \* address;/volatile UWORD * address;/' src/breakpoint.c
+    sed -i 's/UWORD \* restore;/volatile UWORD * restore;/' src/breakpoint.c
+    sed -i 's/static short findBp(UWORD \* addr)/static short findBp(volatile UWORD * addr)/' src/breakpoint.c
+    sed -i 's/void addBreakpoint(UWORD \* addr, short isTmp, UWORD \* restore)/void addBreakpoint(volatile UWORD * addr, short isTmp, volatile UWORD * restore)/' src/breakpoint.c
+    sed -i 's/void delBreakpoint(UWORD \* addr)/void delBreakpoint(volatile UWORD * addr)/' src/breakpoint.c
+    sed -i 's/Printf("break at 0x%08lx\\n", pc);/Printf("break at 0x%08lx\\n", (ULONG)pc);/' src/main.c
+    sed -i 's/Printf("can'"'"'t break at 0x%08lx - %02lx\\n", pc, chk);/Printf("can'"'"'t break at 0x%08lx - %02lx\\n", (ULONG)pc, (ULONG)chk);/' src/main.c
+    sed -i 's/Printf("unknown packet %s\\n", cmd);/Printf("unknown packet %s\\n", (ULONG)cmd);/' src/main.c
+    sed -i 's/Printf("Running GDB server on port %s\\n", p + 1);/Printf("Running GDB server on port %s\\n", (ULONG)(p + 1));/' src/main.c
+    sed -i 's/Printf("Starting RSH server on port %s\\n", sport + 1);/Printf("Starting RSH server on port %s\\n", (ULONG)(sport + 1));/' src/main.c
+}
+
 # INIT Terminal
 clear
 echo -e "\e[1m\e[37m########## \e[31mApollo\e[1;30mCrossDev \e[36m$COMPILER\e[30m v$VERSION \e[37m ###########\e[0m\e[36m"
@@ -16,6 +70,8 @@ mkdir -p $LOGFILES
 rm -f -r $PROJECTS/bgdbserver
 rm -f -r $SOURCES
 mkdir -p $SOURCES
+# Ensure cross-tool binaries are always resolvable in subsequent make steps.
+export PATH="$PREFIX/bin:$PATH"
 cd $SOURCES
 
 # PART 2: Update Linux Packages 
@@ -26,7 +82,15 @@ sudo apt -y install build-essential devscripts debhelper qtbase5-dev qtbase5-dev
 
 # PART 3: Clone Amiga-GCC
 echo -e "\e[1m\e[37m3. Clone Amiga-GCC (Stefan -Bebbo- Franke)\e[0m\e[36m"
-git clone --progress -b $BRANCH $MASTER 2>>$LOGFILES/part3_err.log
+if [ -d "$SOURCES/amiga-gcc/.git" ]; then
+    cd "$SOURCES/amiga-gcc"
+    git fetch --all --prune >>$LOGFILES/part3.log 2>>$LOGFILES/part3_err.log
+    git checkout "$BRANCH" >>$LOGFILES/part3.log 2>>$LOGFILES/part3_err.log
+    git reset --hard "origin/$BRANCH" >>$LOGFILES/part3.log 2>>$LOGFILES/part3_err.log
+    cd "$SOURCES"
+else
+    git clone --progress -b "$BRANCH" "$MASTER" >>$LOGFILES/part3.log 2>>$LOGFILES/part3_err.log
+fi
 
 # Part 4: Compile Amiga-GCC
 echo -e -n "\e[1m\e[37m4. Compile Amiga-GCC: \e[0m\e[36m"
@@ -37,8 +101,30 @@ echo -e -n "\e[0m\e[36mDrop Prefix | "
 make drop-prefix PREFIX=$PREFIX >>$LOGFILES/part4.log 2>>$LOGFILES/part4_err.log
 echo -e -n "\e[0m\e[36mClone Repos (>1 min) | "
 make update $CPU NDK=3.2 PREFIX=$PREFIX >>$LOGFILES/part4.log 2>>$LOGFILES/part4_err.log
+patch_amiga_gcc_sources
 echo -e -n "\e[0m\e[36mBuild Compiler (>5 min) | "
-make all $CPU NDK=3.2 PREFIX=$PREFIX >>$LOGFILES/part4.log 2>>$LOGFILES/part4_err.log
+CFLAGS="-DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+CXXFLAGS="-DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+CPPFLAGS="-DVOID_SIGHANDLER" \
+make all -j1 NDK=3.2 PREFIX=$PREFIX \
+    CFLAGS_FOR_BUILD="-std=gnu17 -DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+    HOST_CFLAGS="-std=gnu17 -DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+    HOST_CXXFLAGS="-std=gnu++17 -DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+    STAGE1_CHECKING="--disable-checking" >>$LOGFILES/part4.log 2>>$LOGFILES/part4_err.log
+
+# GCC 15 host can hit an ICE in libstdc++-v3/src/c++11/cxx11-shim_facets.cc; retry once with lower target C++ optimization.
+if grep -q "cxx11-shim_facets.cc:.*internal compiler error" "$LOGFILES/part4.log"; then
+    echo "retry make all with reduced target C++ optimization after ICE in cxx11-shim_facets.cc" >>$LOGFILES/part4.log
+    CFLAGS="-DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+    CXXFLAGS="-DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+    CPPFLAGS="-DVOID_SIGHANDLER" \
+    make all -j1 NDK=3.2 PREFIX=$PREFIX \
+        CFLAGS_FOR_BUILD="-std=gnu17 -DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+        HOST_CFLAGS="-std=gnu17 -DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+        HOST_CXXFLAGS="-std=gnu++17 -DVOID_SIGHANDLER -U_GLIBCXX_ASSERTIONS -Wno-error=incompatible-pointer-types" \
+        CXXFLAGS_FOR_TARGET="-O0 -fomit-frame-pointer" \
+        STAGE1_CHECKING="--disable-checking" >>$LOGFILES/part4.log 2>>$LOGFILES/part4_err.log
+fi
 echo -e "\e[0m\e[36mAdd LibDebug\e[0m]"
 make libdebug PREFIX=$PREFIX >>$LOGFILES/part4.log 2>>$LOGFILES/part4_err.log
 
@@ -46,20 +132,22 @@ make libdebug PREFIX=$PREFIX >>$LOGFILES/part4.log 2>>$LOGFILES/part4_err.log
 echo -e "\e[1m\e[37m5. Adding MUI5\e[0m\e[36m"
 cd $SOURCES/amiga-gcc
 make sdk=mui PREFIX=$PREFIX >>$LOGFILES/part5.log 2>>$LOGFILES/part5_err.log
+mkdir -p $PREFIX/$TARGET/include/mui
 cp -r -f $SOURCES/amiga-gcc/build/mui/SDK/MUI/C/include/mui/* $PREFIX/$TARGET/include/mui >>$LOGFILES/part5.log 2>>$LOGFILES/part5_err.log
 
 # Part 6: PortLibs (amiga-gcc takes care of Open-GL, SDL and GDB - we add Freetype, ZLib and BZip2)
 echo -e -n "\e[1m\e[37m6. Adding Porting Libs: "
 cd $PREFIX
+mkdir -p $PREFIX/$TARGET/include $PREFIX/$TARGET/lib $PREFIX/$TARGET/include/clib $PREFIX/$TARGET/include/libraries
 echo -e -n "\e[0m\e[36mGL | "
-cp -r -f $PREFIX/include/GL $PREFIX/$TARGET/include/GL >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
+if [ -d $PREFIX/include/GL ]; then cp -r -f $PREFIX/include/GL $PREFIX/$TARGET/include/GL >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log; fi
 echo -e -n "\e[0m\e[36mGDB | "
-cp -r -f $PREFIX/include/gdb $PREFIX/$TARGET/include/GDB >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
+if [ -d $PREFIX/include/gdb ]; then cp -r -f $PREFIX/include/gdb $PREFIX/$TARGET/include/GDB >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log; fi
 echo -e -n "\e[0m\e[36mSDL | "
-cp -r -f $PREFIX/include/SDL $PREFIX/$TARGET/include/SDL >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
-cp -r -f $PREFIX/lib/libSDL* $PREFIX/$TARGET/lib >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
-rm -r -f $PREFIX/lib/libSDL* >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
-rm -r -f $PREFIX/include >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
+if [ -d $PREFIX/include/SDL ]; then cp -r -f $PREFIX/include/SDL $PREFIX/$TARGET/include/SDL >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log; fi
+if ls $PREFIX/lib/libSDL* >/dev/null 2>&1; then cp -r -f $PREFIX/lib/libSDL* $PREFIX/$TARGET/lib >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log; fi
+if ls $PREFIX/lib/libSDL* >/dev/null 2>&1; then rm -r -f $PREFIX/lib/libSDL* >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log; fi
+if [ -d $PREFIX/include ]; then rm -r -f $PREFIX/include >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log; fi
 
 echo -e -n "\e[0m\e[36mSDL-TTF | "
 cd $ARCHIVES/SDL-TTF
@@ -98,7 +186,7 @@ cp -r -f $ARCHIVES/zlib-source $SOURCES/zlib-source
 cd $SOURCES/zlib-source
 CC=$PREFIX/bin/m68k-amigaos-gcc \
 AR=$PREFIX/bin/m68k-amigaos-ar \
-RANLIB=CC=$PREFIX/bin/m68k-amigaos-ranlib \
+RANLIB=$PREFIX/bin/m68k-amigaos-ranlib \
 CFLAGS="-noixemul -m68040 -O2 -ffast-math -fomit-frame-pointer" \
 ./configure >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
 make all $CPU >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
@@ -108,8 +196,9 @@ cp -r zlib.h $PREFIX/$TARGET/include >>$LOGFILES/part6.log 2>>$LOGFILES/part6_er
 cp -r zconf.h $PREFIX/$TARGET/include >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
 
 echo -e "\e[0m\e[36mTimidity\e[0m"
-mkdir $SOURCES/timidity-source
+mkdir -p $SOURCES/timidity-source
 cp -r -f $ARCHIVES/timidity-source/src/* $SOURCES/timidity-source
+patch_timidity_sources
 cd $SOURCES/timidity-source
 make -f Makefile.apollocrossdev >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
 cp libtimidity.a $PREFIX/$TARGET/lib >>$LOGFILES/part6.log 2>>$LOGFILES/part6_err.log
@@ -119,15 +208,17 @@ cp -f *.h $PREFIX/$TARGET/include/timidity
 # PART 7: NDK
 echo -e "\e[1m\e[37m7. Development Kits\e[0m\e[36m"
 cd $PREFIX/$TARGET
-git clone --progress https://github.com/WDrijver/DevPac >>$LOGFILES/part7.log 2>>$LOGFILES/part7_err.log
+if [ ! -d $PREFIX/$TARGET/DevPac/.git ]; then git clone --progress https://github.com/WDrijver/DevPac >>$LOGFILES/part7.log 2>>$LOGFILES/part7_err.log; fi
 cd $ARCHIVES
-cp -r -f P96/* $PREFIX/$TARGET/include >>$LOGFILES/part7.log 2>>$LOGFILES/part7_err.log
+cp -r -f P96/autodocs P96/e P96/fd P96/inline P96/lvo_p96.i P96/pragmas P96/proto $PREFIX/$TARGET/include >>$LOGFILES/part7.log 2>>$LOGFILES/part7_err.log
+cp -r -f P96/clib/* $PREFIX/$TARGET/include/clib >>$LOGFILES/part7.log 2>>$LOGFILES/part7_err.log
+cp -r -f P96/libraries/* $PREFIX/$TARGET/include/libraries >>$LOGFILES/part7.log 2>>$LOGFILES/part7_err.log
 cp -r -f cmake/* $PREFIX/lib >>$LOGFILES/part7.log 2>>$LOGFILES/part7_err.log
 
 # Part 8: ApolloExplorer
 echo -e "\e[1m\e[37m8. ApolloExplorer\e[0m\e[36m"
 cd $WORKSPACE/$PROJECTS
-git clone --progress https://github.com/ronybeck/ApolloExplorer >>$LOGFILES/part8.log 2>>$LOGFILES/part8_err.log
+if [ ! -d $WORKSPACE/$PROJECTS/ApolloExplorer/.git ]; then git clone --progress https://github.com/ronybeck/ApolloExplorer >>$LOGFILES/part8.log 2>>$LOGFILES/part8_err.log; fi
 cd $WORKSPACE/$PROJECTS/ApolloExplorer
 qmake >>$LOGFILES/part8.log 2>>$LOGFILES/part8_err.log
 make >>$LOGFILES/part8.log 2>>$LOGFILES/part8_err.log
@@ -135,8 +226,9 @@ make >>$LOGFILES/part8.log 2>>$LOGFILES/part8_err.log
 # Part 9: BGDBServer
 echo -e "\e[1m\e[37m9. BGDG Server\e[0m\e[36m"
 cd $WORKSPACE/$PROJECTS
-git clone --progress https://github.com/WDrijver/bgdbserver >>$LOGFILES/part9.log 2>>$LOGFILES/part9_err.log
+if [ ! -d $WORKSPACE/$PROJECTS/bgdbserver/.git ]; then git clone --progress https://github.com/WDrijver/bgdbserver >>$LOGFILES/part9.log 2>>$LOGFILES/part9_err.log; fi
 cd $WORKSPACE/$PROJECTS/bgdbserver
+patch_bgdbserver_sources
 make >>$LOGFILES/part9.log 2>>$LOGFILES/part9_err.log
 
 # PART 10: Cleanup