geary build failure - iconv not found

I'm unable to build geary on edge (but it works on 3.17), pkg-config fails to find iconv (nothing in aports seems to provide "iconv.pc"?)

Run-time dependency appstream-glib found: NO

meson.build:75:0: ERROR: Dependency lookup for appstream-glib with method 'pkgconfig' failed: Could not generate cargs for appstream-glib:
Package iconv was not found in the pkg-config search path.
Perhaps you should add the directory containing `iconv.pc'
to the PKG_CONFIG_PATH environment variable
Package 'iconv', required by 'libarchive', not found