Enforce consistency of `gl` providers (#44307)

* glew: rework dependency on gl

This simplifies the package and ensures a single gl implementation is
pulled in. Before we were adding direct dependencies, and those are
not unified through the virtual.

* mesa-demos: rework dependency on gl

This simplifies the package and ensures a single gl implementation is
pulled in. Before we were adding direct dependencies, and those are
not unified through the virtual.

* mesa-glu: rework dependency on gl

This simplifies the package and ensures a single gl implementation is
pulled in. Before we were adding direct dependencies, and those are
not unified through the virtual.

* paraview: fix dependency on glew

* mesa: group dependency on when("+glx")

* Add missing dependency on libxml2

* paraview: remove the "osmesa" and "egl" variant

Instead, enforce consistency using the "gl" virtual that allows
only one provider.

* visit: remove osmesa variant

* Disable paraview in the aws-isc stacks

* data-vis-sdk: rework constrains to enforce front-ends

* e4s-power: remove redundant paraview

* Pipelines: update osmesa variants

* trilinos-catalyst-ioss-adapter: make gl a run dependency

8 files changed, 46 insertions, 105 deletions

diff --git a/var/spack/repos/builtin/packages/glew/package.py b/var/spack/repos/builtin/packages/glew/package.py
index 6e2e41779f..7183933c4b 100644
--- a/var/spack/repos/builtin/packages/glew/package.py
+++ b/var/spack/repos/builtin/packages/glew/package.py
@@ -2,9 +2,6 @@
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
-import sys
-
 from spack.package import *
 
 
@@ -23,29 +20,9 @@ class Glew(CMakePackage):
     version("2.1.0", sha256="04de91e7e6763039bc11940095cd9c7f880baba82196a7765f727ac05a993c95")
     version("2.0.0", sha256="c572c30a4e64689c342ba1624130ac98936d7af90c3103f9ce12b8a0c5736764")
 
-    variant(
-        "gl",
-        default="glx" if sys.platform.startswith("linux") else "other",
-        values=("glx", "osmesa", "egl", "other"),
-        multi=False,
-        description="The OpenGL provider to use",
-    )
-    conflicts("^osmesa", when="gl=glx")
-    conflicts("^osmesa", when="gl=egl")
-    conflicts("^osmesa", when="gl=other")
-    conflicts("^glx", when="gl=osmesa")
-    conflicts("^glx", when="gl=other")
-    conflicts("^glx", when="gl=egl")
-    conflicts("^egl", when="gl=glx")
-    conflicts("^egl", when="gl=osmesa")
-    conflicts("^egl", when="gl=other")
-
     depends_on("gl")
-    depends_on("osmesa", when="gl=osmesa")
-    depends_on("glx", when="gl=glx")
-    depends_on("libx11", when="gl=glx")
-    depends_on("xproto", when="gl=glx")
-    depends_on("egl", when="gl=egl")
+    depends_on("libx11", when="^[virtuals=gl] glx")
+    depends_on("xproto", when="^[virtuals=gl] glx")
 
     # glu is already forcibly disabled in the CMakeLists.txt.  This prevents
     # it from showing up in the .pc file
@@ -56,15 +33,15 @@ class Glew(CMakePackage):
         args = [
             self.define("BUILD_UTILS", True),
             self.define("GLEW_REGAL", False),
-            self.define("GLEW_EGL", "gl=egl" in spec),
+            self.define("GLEW_EGL", spec.satisfies("^[virtuals=gl] egl")),
             self.define("OPENGL_INCLUDE_DIR", spec["gl"].headers.directories[0]),
             self.define("OPENGL_gl_LIBRARY", spec["gl"].libs[0]),
             self.define("OPENGL_opengl_LIBRARY", "IGNORE"),
             self.define("OPENGL_glx_LIBRARY", "IGNORE"),
             self.define("OPENGL_glu_LIBRARY", "IGNORE"),
-            self.define("GLEW_OSMESA", "gl=osmesa" in spec),
+            self.define("GLEW_OSMESA", spec.satisfies("^[virtuals=gl] osmesa")),
         ]
-        if "gl=egl" in spec:
+        if spec.satisfies("^[virtuals=gl] egl"):
             args.append(
                 self.define("OPENGL_egl_LIBRARY", [spec["egl"].libs[0], spec["egl"].libs[1]])
             )
@@ -76,4 +53,4 @@ class Glew(CMakePackage):
     def flag_handler(self, name, flags):
         if name == "ldflags" and self.spec.satisfies("platform=darwin ^apple-gl"):
             flags.append("-framework OpenGL")
-        return (flags, None, None)
+        return flags, None, None
diff --git a/var/spack/repos/builtin/packages/mesa-demos/package.py b/var/spack/repos/builtin/packages/mesa-demos/package.py
index c85b2eb2e3..60a923e06a 100644
--- a/var/spack/repos/builtin/packages/mesa-demos/package.py
+++ b/var/spack/repos/builtin/packages/mesa-demos/package.py
@@ -2,8 +2,6 @@
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-import sys
-
 from spack.package import *
 
 
@@ -20,18 +18,6 @@ class MesaDemos(AutotoolsPackage):
     version("8.2.0", sha256="5a9f71b815d968d0c3b77edfcc3782d0211f8520b00da9e554ccfed80c8889f6")
     version("8.1.0", sha256="cc5826105355830208c90047fc38c5b09fa3ab0045366e7e859104935b00b76d")
 
-    variant(
-        "gl",
-        default="glx" if sys.platform.startswith("linux") else "osmesa",
-        values=("glx", "osmesa", "other"),
-        multi=False,
-        description="The OpenGL provider to use",
-    )
-    conflicts("^osmesa", when="gl=glx")
-    conflicts("^osmesa", when="gl=other")
-    conflicts("^glx", when="gl=osmesa")
-    conflicts("^glx", when="gl=other")
-
     depends_on("autoconf", type="build")
     depends_on("automake", type="build")
     depends_on("libtool", type="build")
@@ -39,10 +25,8 @@ class MesaDemos(AutotoolsPackage):
     depends_on("pkgconfig", type="build")
 
     depends_on("gl")
-    depends_on("osmesa", when="gl=osmesa")
-    depends_on("glx", when="gl=glx")
-    depends_on("libx11", when="gl=glx")
-    depends_on("libxext", when="gl=glx")
+    depends_on("libx11", when="^[virtuals=gl] glx")
+    depends_on("libxext", when="^[virtuals=gl] glx")
 
     depends_on("glu")
     depends_on("glew@1.5.4:")
@@ -64,11 +48,11 @@ class MesaDemos(AutotoolsPackage):
             "--disable-rbug",
             "--without-glut",
         ]
-        if "gl=glx" in spec:
+        if spec.satisfies("^[virtuals=gl] glx"):
             args.append("--enable-x11")
         else:
             args.append("--disable-x11")
-        if "gl=osmesa" in spec:
+        if spec.satisfies("^[virtuals=gl] osmesa"):
             args.append("--enable-osmesa")
         else:
             args.append("--disable-osmesa")
diff --git a/var/spack/repos/builtin/packages/mesa-glu/package.py b/var/spack/repos/builtin/packages/mesa-glu/package.py
index 071703aa5f..7393398e91 100644
--- a/var/spack/repos/builtin/packages/mesa-glu/package.py
+++ b/var/spack/repos/builtin/packages/mesa-glu/package.py
@@ -2,9 +2,6 @@
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
-import sys
-
 from spack.package import *
 
 
@@ -18,22 +15,7 @@ class MesaGlu(AutotoolsPackage):
     version("9.0.1", sha256="f6f484cfcd51e489afe88031afdea1e173aa652697e4c19ddbcb8260579a10f7")
     version("9.0.0", sha256="4387476a1933f36fec1531178ea204057bbeb04cc2d8396c9ea32720a1f7e264")
 
-    variant(
-        "gl",
-        default="glx" if sys.platform.startswith("linux") else "other",
-        values=("glx", "osmesa", "other"),
-        multi=False,
-        description="The OpenGL provider to use",
-    )
-    conflicts("^osmesa", when="gl=glx")
-    conflicts("^osmesa", when="gl=other")
-    conflicts("^glx", when="gl=osmesa")
-    conflicts("^glx", when="gl=other")
-
     depends_on("gl@3:")
-    depends_on("osmesa", when="gl=osmesa")
-    depends_on("glx", when="gl=glx")
-
     provides("glu@1.3")
 
     # When using -std=c++17, using register long will throw an error. This
@@ -43,7 +25,7 @@ class MesaGlu(AutotoolsPackage):
     def configure_args(self):
         args = ["--disable-libglvnd"]
 
-        if "gl=osmesa" in self.spec:
+        if self.spec.satisfies("^[virtuals=gl] osmesa"):
             args.append("--enable-osmesa")
         else:
             args.append("--disable-osmesa")
diff --git a/var/spack/repos/builtin/packages/mesa/package.py b/var/spack/repos/builtin/packages/mesa/package.py
index b46be01968..dbbcee64cb 100644
--- a/var/spack/repos/builtin/packages/mesa/package.py
+++ b/var/spack/repos/builtin/packages/mesa/package.py
@@ -62,6 +62,7 @@ class Mesa(MesonPackage):
     depends_on("unwind")
     depends_on("expat")
     depends_on("zlib-api")
+    depends_on("libxml2")
 
     # Internal options
     variant("llvm", default=True, description="Enable LLVM.")
@@ -111,12 +112,13 @@ class Mesa(MesonPackage):
         depends_on("libllvm@:12", when="@:21")
         depends_on("libllvm@:17", when="@:23")
 
-    depends_on("libx11", when="+glx")
-    depends_on("libxcb", when="+glx")
-    depends_on("libxext", when="+glx")
-    depends_on("libxt", when="+glx")
-    depends_on("xrandr", when="+glx")
-    depends_on("glproto@1.4.14:", when="+glx")
+    with when("+glx"):
+        depends_on("libx11")
+        depends_on("libxcb")
+        depends_on("libxext")
+        depends_on("libxt")
+        depends_on("xrandr")
+        depends_on("glproto@1.4.14:")
 
     # version specific issue
     # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96130
diff --git a/var/spack/repos/builtin/packages/of-catalyst/package.py b/var/spack/repos/builtin/packages/of-catalyst/package.py
index d7a3821736..b210baa5d3 100644
--- a/var/spack/repos/builtin/packages/of-catalyst/package.py
+++ b/var/spack/repos/builtin/packages/of-catalyst/package.py
@@ -32,7 +32,11 @@ class OfCatalyst(CMakePackage):
 
     depends_on("openfoam@1806", when="@1806", type=("build", "link", "run"))
     depends_on("openfoam@develop", when="@develop", type=("build", "link", "run"))
-    depends_on("paraview@5.5:+osmesa~qt", when="+full")
+
+    with when("+full"):
+        depends_on("paraview@5.5: ~qt")
+        depends_on("gl")
+        requires("^[virtuals=gl] osmesa")
 
     root_cmakelists_dir = "src/catalyst"
 
diff --git a/var/spack/repos/builtin/packages/paraview/package.py b/var/spack/repos/builtin/packages/paraview/package.py
index d9482a5c51..3ce188bbf1 100644
--- a/var/spack/repos/builtin/packages/paraview/package.py
+++ b/var/spack/repos/builtin/packages/paraview/package.py
@@ -66,8 +66,6 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
     variant("python", default=False, description="Enable Python support", when="@5.6:")
     variant("fortran", default=False, description="Enable Fortran support")
     variant("mpi", default=True, description="Enable MPI support")
-    variant("osmesa", default=False, description="Enable OSMesa support")
-    variant("egl", default=False, description="Enable EGL in the OpenGL library being used")
     variant("qt", default=False, description="Enable Qt (gui) support")
     variant("opengl2", default=True, description="Enable OpenGL2 backend")
     variant("examples", default=False, description="Build examples")
@@ -187,16 +185,12 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
 
     depends_on("gl@3.2:", when="+opengl2")
     depends_on("gl@1.2:", when="~opengl2")
-    depends_on("glew", when="~egl")
-    depends_on("glew gl=egl", when="+egl")
+    depends_on("glew")
 
-    depends_on("osmesa", when="+osmesa")
     for p in ["linux", "cray"]:
-        depends_on("glx", when="~egl ~osmesa platform={}".format(p))
-        depends_on("libxt", when="~egl ~osmesa platform={}".format(p))
-    conflicts("+qt", when="+osmesa")
-    conflicts("+qt", when="+egl")
-    conflicts("+egl", when="+osmesa")
+        depends_on("libxt", when=f"platform={p} ^[virtuals=gl] glx")
+
+    requires("^[virtuals=gl] glx", when="+qt", msg="Qt support requires GLX")
 
     depends_on("ospray@2.1:2", when="+raytracing")
     depends_on("openimagedenoise", when="+raytracing")
@@ -376,7 +370,7 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
                 if self.spec["hdf5"].satisfies("@1.12:"):
                     flags.append("-DH5_USE_110_API")
 
-        return (flags, None, None)
+        return flags, None, None
 
     def setup_run_environment(self, env):
         # paraview 5.5 and later
@@ -424,19 +418,17 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
 
         def variant_bool(feature, on="ON", off="OFF"):
             """Ternary for spec variant to ON/OFF string"""
-            if feature in spec:
+            if spec.satisfies(feature):
                 return on
             return off
 
-        def nvariant_bool(feature):
-            """Negated ternary for spec variant to OFF/ON string"""
-            return variant_bool(feature, on="OFF", off="ON")
-
         def use_x11():
             """Return false if osmesa or egl are requested"""
-            if "+osmesa" in spec or "+egl" in spec:
-                return "OFF"
-            if spec.satisfies("platform=windows"):
+            if (
+                spec.satisfies("^[virtuals=gl] osmesa")
+                or spec.satisfies("^[virtuals=gl] egl")
+                or spec.satisfies("platform=windows")
+            ):
                 return "OFF"
             return "ON"
 
@@ -444,7 +436,7 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
         includes = variant_bool("+development_files")
 
         cmake_args = [
-            "-DVTK_OPENGL_HAS_OSMESA:BOOL=%s" % variant_bool("+osmesa"),
+            "-DVTK_OPENGL_HAS_OSMESA:BOOL=%s" % variant_bool("^[virtuals=gl] osmesa"),
             "-DVTK_USE_X:BOOL=%s" % use_x11(),
             "-DPARAVIEW_INSTALL_DEVELOPMENT_FILES:BOOL=%s" % includes,
             "-DBUILD_TESTING:BOOL=OFF",
@@ -453,7 +445,7 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
             self.define_from_variant("VISIT_BUILD_READER_Silo", "visitbridge"),
         ]
 
-        if "+egl" in spec:
+        if spec.satisfies("^[virtuals=gl] egl"):
             cmake_args.append("-DVTK_OPENGL_HAS_EGL:BOOL=ON")
 
         if spec.satisfies("@5.12:"):
@@ -530,7 +522,7 @@ class Paraview(CMakePackage, CudaPackage, ROCmPackage):
 
         # The assumed qt version changed to QT5 (as of paraview 5.2.1),
         # so explicitly specify which QT major version is actually being used
-        if "+qt" in spec:
+        if spec.satisfies("+qt"):
             cmake_args.extend(["-DPARAVIEW_QT_VERSION=%s" % spec["qt"].version[0]])
 
         if "+fortran" in spec:
diff --git a/var/spack/repos/builtin/packages/trilinos-catalyst-ioss-adapter/package.py b/var/spack/repos/builtin/packages/trilinos-catalyst-ioss-adapter/package.py
index 891929bdb4..c971f46adc 100644
--- a/var/spack/repos/builtin/packages/trilinos-catalyst-ioss-adapter/package.py
+++ b/var/spack/repos/builtin/packages/trilinos-catalyst-ioss-adapter/package.py
@@ -17,7 +17,9 @@ class TrilinosCatalystIossAdapter(CMakePackage):
 
     depends_on("bison", type="build")
     depends_on("flex", type="build")
-    depends_on("paraview+mpi+python+osmesa")
+    depends_on("paraview+mpi+python")
+    depends_on("gl", type="run")
+    requires("^[virtuals=gl] osmesa", msg="OSMesa is required for paraview")
     depends_on("py-numpy", type=("build", "run"))
     # Here we avoid paraview trying to use netcdf-c~parallel-netcdf
     # which is netcdf-c's default, even though paraview depends on 'netcdf-c'
diff --git a/var/spack/repos/builtin/packages/visit/package.py b/var/spack/repos/builtin/packages/visit/package.py
index 987f7f7250..5163725ab8 100644
--- a/var/spack/repos/builtin/packages/visit/package.py
+++ b/var/spack/repos/builtin/packages/visit/package.py
@@ -75,7 +75,6 @@ class Visit(CMakePackage):
     generator("ninja")
 
     variant("gui", default=True, description="Enable VisIt's GUI")
-    variant("osmesa", default=False, description="Use OSMesa for off-screen CPU rendering")
     variant("adios2", default=True, description="Enable ADIOS2 file format")
     variant("hdf5", default=True, description="Enable HDF5 file format")
     variant("netcdf", default=True, description="Enable NetCDF file format")
@@ -105,14 +104,13 @@ class Visit(CMakePackage):
     # Fix const-correctness in VTK interface
     patch("vtk-8.2-constcorrect.patch", when="@3.3.3 ^vtk@8.2.1a")
 
-    # Exactly one of 'gui' or 'osmesa' has to be enabled
-    conflicts("+gui", when="+osmesa")
+    conflicts(
+        "+gui", when="^[virtuals=gl] osmesa", msg="GUI cannot be activated with OSMesa front-end"
+    )
 
     depends_on("cmake@3.14.7:", type="build")
     depends_on("mpi", when="+mpi")
 
-    requires("^[virtuals=gl] osmesa", when="+osmesa")
-
     # VTK flavors
     depends_on("vtk@8.1:8 +opengl2")
     depends_on("vtk +qt", when="+gui")
@@ -125,7 +123,7 @@ class Visit(CMakePackage):
     depends_on(
         "vtk",
         patches=[patch("vtk_rendering_opengl2_x11.patch")],
-        when="~osmesa platform=linux ^vtk@8",
+        when="platform=linux ^[virtuals=gl] glx ^vtk@8",
     )
     depends_on("vtk", patches=[patch("vtk_wrapping_python_x11.patch")], when="+python ^vtk@8")
 
@@ -296,7 +294,7 @@ class Visit(CMakePackage):
                 self.define("OPENGL_glu_LIBRARY", spec["glu"].libs[0]),
             ]
         )
-        if "+osmesa" in spec:
+        if spec.satisfies("^[virtuals=gl] osmesa"):
             args.extend(
                 [
                     self.define("HAVE_OSMESA", True),