net/vde2: add vde2-devel subport

Add a vde2-devel subport for a recent upstream GitHub commit using
the CMake build system. Keep vde2 on the latest tagged release and fix
that release build by forcing C17, since the old sources do not build
as C23.

Patch the devel CMake build on Darwin to avoid malformed linker flags
for libvdehist.

net/vde2/Portfile

@@ -21,20 +21,50 @@ checksums           rmd160  257d008bd8ce5a56f1ab7086a7f69a01f639294c \
                     sha256  a7d2cc4c3d0c0ffe6aff7eb0029212f2b098313029126dcd12dc542723972379 \
                     size    234790
 
-use_autoreconf      yes
+conflicts           ${name}-devel
+
+subport ${name}-devel {
+    PortGroup       cmake 1.1
+
+    github.setup    virtualsquare vde-2 6ad51c2fd557734011c140afc7b502d84cc5d3b0
+    version         20260323-[string range ${github.version} 0 7]
+    revision        0
+    conflicts       ${name}
+
+    checksums       rmd160  8a7d2823083e70408c9297b6870d3fde86c29585 \
+                    sha256  81784c5618e9c7ec1e129a3b28d7a94d109671bbf85177aac4ce94d22594dd21 \
+                    size    233059
+
+    # Fix malformed Darwin linker flags in upstream's CMake build.
+    patchfiles      patch-src-lib-CMakeLists.txt.diff
+}
 
 default_variants    +pcap
 
-configure.args      --disable-experimental \
+if {${subport} eq "${name}-devel"} {
+    configure.args-append \
+                    -DENABLE_EXPERIMENTAL=OFF \
+                    -DENABLE_TUNTAP=OFF \
+                    -DENABLE_PCAP=OFF \
+                    -DENABLE_CRYPTCAB=OFF
+} else {
+    use_autoreconf  yes
+
+    # The release uses old-style empty function prototypes that fail as C23.
+    configure.cflags-append \
+                    -std=gnu17
+
+    configure.args  --disable-experimental \
                     --disable-tuntap \
                     --disable-pcap \
                     --disable-cryptcab
+}
 
 # See https://github.com/virtualsquare/vde-2/issues/6
 use_parallel_build  no
 
 post-destroot {
-    set docdir ${destroot}${prefix}/share/doc/${name}
+    set docdir ${destroot}${prefix}/share/doc/${subport}
     xinstall -d ${docdir}
     xinstall -m 644 -W ${worksrcpath} \
                     COPYING \
@@ -55,14 +85,26 @@ post-destroot {
 
 variant tuntap description {Enable support for TAP devices} {
     depends_lib-append      port:tuntaposx
-    configure.args-replace  --disable-tuntap --enable-tuntap
+    if {${subport} eq "${name}-devel"} {
+        configure.args-replace  -DENABLE_TUNTAP=OFF -DENABLE_TUNTAP=ON
+    } else {
+        configure.args-replace  --disable-tuntap --enable-tuntap
+    }
 }
 
 variant pcap description {Enable support for packet capturing} {
     depends_lib-append      port:libpcap
-    configure.args-replace  --disable-pcap --enable-pcap
+    if {${subport} eq "${name}-devel"} {
+        configure.args-replace  -DENABLE_PCAP=OFF -DENABLE_PCAP=ON
+    } else {
+        configure.args-replace  --disable-pcap --enable-pcap
+    }
 }
 
 variant experimental description {Enable support for experimental features} {
-    configure.args-replace  --disable-experimental --enable-experimental
+    if {${subport} eq "${name}-devel"} {
+        configure.args-replace  -DENABLE_EXPERIMENTAL=OFF -DENABLE_EXPERIMENTAL=ON
+    } else {
+        configure.args-replace  --disable-experimental --enable-experimental
+    }
 }

net/vde2/files/patch-src-lib-CMakeLists.txt.diff

@@ -0,0 +1,14 @@
+--- src/lib/CMakeLists.txt.orig
++++ src/lib/CMakeLists.txt
+@@ -21,10 +21,9 @@ install(TARGETS vdesnmp
+ 
+ add_library(vdehist SHARED libvdehist.c)
+ target_link_libraries(vdehist PRIVATE vdecommon)
+ if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+-  target_compile_options(vdehist PRIVATE -Wall -O2 -g -O2 -fno-common -DPIC)
+-  target_link_options(vdehist PRIVATE -Wl,-undefined -Wl,dynamic_lookup -Wl,-no_fixup_chains -Wl,-force_load -O2 -g -O2)
++  target_link_options(vdehist PRIVATE -Wl,-undefined,dynamic_lookup)
+ endif()
+ set_target_properties(vdehist PROPERTIES VERSION 0.0.1 SOVERSION 0)
+ configure_file(vdehist.pc.in ${CMAKE_CURRENT_BINARY_DIR}/vdehist.pc @ONLY)
+ install(FILES ${CMAKE_CURRENT_BINARY_DIR}/vdehist.pc