librsvg-devel: builds fail for older macOS releases, due to libcurl issue: dyld: lazy symbol binding failed: Symbol not found: _SCDynamicStoreCopyProxies

[mascguy (Christopher Nielsen)]

Details for 10.9, though the pattern is identical for 10.8 and earlier too:

cargo --locked build --verbose  --release --lib \
&& cd librsvg-devel/work/librsvg-2.56.3 && /bin/sh ./libtool  --tag=CC --mode=link /opt/local/bin/clang-mp-16
-isysroot/ -arch x86_64  -lobjc -Wl,-syslibroot,/ -arch x86_64 -o librsvg_c_api.la _rsvg_dummy.lo
&& mv librsvg-devel/work/librsvg-2.56.3/target/x86_64-apple-darwin/release/librsvg.a .libs/librsvg_c_api.a

dyld: lazy symbol binding failed: Symbol not found: _SCDynamicStoreCopyProxies
  Referenced from: /opt/local/lib/libcurl.4.dylib
  Expected in: flat namespace

dyld: Symbol not found: _SCDynamicStoreCopyProxies
  Referenced from: /opt/local/lib/libcurl.4.dylib
  Expected in: flat namespace

Testing locally on 10.9, with the published binary for curl, I see the same issue. But port rev-upgrade doesn't report any issues, so it's not immediately apparent whether curl needs to be rev-bumped... or whether a recent change caused this issue.