postgresqlPackages.postgis: fix cross-compilation (#424800)

    ./autogen.sh

  '';

  configureFlags = [

    "--with-pgconfig=${postgresql.pg_config}/bin/pg_config"

    "--with-gdalconfig=${gdal}/bin/gdal-config"

    "--with-jsondir=${json_c.dev}"

    "--disable-extension-upgrades-install"

  ] ++ lib.optional withSfcgal "--with-sfcgal=${sfcgal}/bin/sfcgal-config";

  configureFlags =

    let

      isCross = stdenv.hostPlatform.config != stdenv.buildPlatform.config;

    in

    [

      (lib.enableFeature false "extension-upgrades-install")

      (lib.withFeatureAs true "pgconfig" "${postgresql.pg_config}/bin/pg_config")

      (lib.withFeatureAs true "gdalconfig" "${gdal}/bin/gdal-config")

      (lib.withFeatureAs true "jsondir" (lib.getDev json_c))

      (lib.withFeatureAs true "xml2config" (lib.getExe' (lib.getDev libxml2) "xml2-config"))

      (lib.withFeatureAs withSfcgal "sfcgal" "${sfcgal}/bin/sfcgal-config")

      (lib.withFeature (!isCross) "json") # configure: error: cannot check for file existence when cross compiling

    ];

  makeFlags = [

    "PERL=${perl}/bin/perl"