g2: add dependencies, build options, and v3.4.6 release (#39717)

* adding bacio to g2 dependencies
* edited documentation
* added version 3.4.6
* starting with 3.4.6, can use any version of jasper
* adding w3emc dependency for versions up to 3.4.5
* removed t-brown as maintainer at his request

var/spack/repos/builtin/packages/g2/package.py

@@ -7,22 +7,40 @@
 
 
 class G2(CMakePackage):
-    """Utilities for coding/decoding GRIB2 messages. This library contains
-    Fortran 90 decoder/encoder routines for GRIB edition 2, as well as
-    indexing/searching utility routines.
+    """The NCEPLIBS-g2 library reads and writes GRIB2 files. GRIdded Binary or General
+    Regularly-distributed Information in Binary form (GRIB) is a data format for
+    meteorological and forecast data, standardized by the World Meteorological
+    Organization (WMO).
 
     This is part of the NCEPLIBS project."""
 
     homepage = "https://noaa-emc.github.io/NCEPLIBS-g2"
     url = "https://github.com/NOAA-EMC/NCEPLIBS-g2/archive/refs/tags/v3.4.3.tar.gz"
 
-    maintainers("t-brown", "AlexanderRichert-NOAA", "Hang-Lei-NOAA", "edwardhartnett")
+    maintainers("AlexanderRichert-NOAA", "Hang-Lei-NOAA", "edwardhartnett")
 
+    version("3.4.6", sha256="c4b03946365ce0bacf1e10e8412a5debd72d8671d1696aa4fb3f3adb119175fe")
     version("3.4.5", sha256="c18e991c56964953d778632e2d74da13c4e78da35e8d04cb742a2ca4f52737b6")
     version("3.4.3", sha256="679ea99b225f08b168cbf10f4b29f529b5b011232f298a5442ce037ea84de17c")
 
-    depends_on("jasper@:2.0.32")
+    variant(
+        "build_with_w3emc",
+        description="Enable GRIB1 conversion routine",
+        default=True,
+        when="@3.4.5:",
+    )
+
     depends_on("libpng")
+    depends_on("bacio")
+    depends_on("jasper@:2.0.32", when="@:3.4.5")
+    depends_on("jasper", when="@3.4.6:")
+    depends_on("w3emc", when="@:3.4.5")
+
+    def cmake_args(self):
+        args = []
+
+        if self.spec.satisfies("@3.4.5:"):
+            args.append(self.define_from_variant("BUILD_WITH_W3EMC", "build_with_w3emc"))
 
     def setup_run_environment(self, env):
         for suffix in ("4", "d"):