Fix restarting simulation from command line

This commit fixes a broken option in ClimaCoupler. ClimaCoupler would
not restart correctly when the details for the restart were passed via
command line, unless `restart_dir` was the same as `output_dir_root`.

Version 0.29.1 of ClimaAtmos introduces a way to go around the
underlying problem that introduced that bug and also introduced a second
limitation to the restart system.

Closes #1218

Author: Sbozzolo

experiments/ClimaEarth/setup_run.jl

@@ -242,9 +242,17 @@ function setup_and_run(config_dict::AbstractDict)
             t_start = restart_t
         end
 
-        # TODO: Find a cleaner way to do this instead of having a second restart
-        # just for atmos
-        atmos_config_dict["restart_file"] = climaatmos_restart_path(output_dir_root, restart_t)
+        if pkgversion(CA) >= v"0.29.1"
+            # We only support a round number of seconds
+            isinteger(float(t_start)) || error("Cannot restart from a non integer number of seconds")
+            t_start_int = Int(float(t_start))
+            atmos_config_dict["t_start"] = "$(t_start_int)secs"
+        else
+            # There was no `t_start`, so we have to use a workaround for this.
+            # This does not support passing the command-line arguments (unless
+            # restart_dir is exactly the same as output_dir_root)
+            atmos_config_dict["restart_file"] = climaatmos_restart_path(output_dir_root, restart_t)
+        end
 
         @info "Starting from t_start $(t_start)"
     end

experiments/ClimaEarth/test/restart.jl

@@ -47,11 +47,26 @@ four_steps["dt"] = "180secs"
 four_steps["dt_cpl"] = "180secs"
 four_steps["t_end"] = "720secs"
 four_steps["dt_rad"] = "180secs"
+four_steps["checkpoint_dt"] = "720secs"
+four_steps["coupler_output_dir"] = tmpdir
 four_steps["job_id"] = "four_steps"
 
+println("Simulating four steps")
 cs_four_steps = setup_and_run(four_steps)
 
-println("Simulating two steps")
+# Check that we can pick up a simulation by providing t_restart and restart_dir
+println("Simulating four steps, options from command line")
+four_steps_reading = deepcopy(four_steps)
+
+four_steps_reading["t_end"] = "900secs"
+four_steps_reading["restart_dir"] = cs_four_steps.dirs.checkpoints
+four_steps_reading["restart_t"] = 720
+four_steps_reading["job_id"] = "four_steps_reading"
+
+cs_four_steps_reading = setup_and_run(four_steps_reading)
+@testset "Restarts from command line arguments" begin
+    @test cs_four_steps_reading.tspan[1] == cs_four_steps.tspan[2]
+end
 
 # Now, two steps plus one
 two_steps = deepcopy(default_config)
@@ -65,9 +80,10 @@ two_steps["checkpoint_dt"] = "360secs"
 two_steps["job_id"] = "two_steps"
 
 # Copying since setup_and_run changes its content
+println("Simulating two steps")
 cs_two_steps1 = setup_and_run(two_steps)
 
-println("Reading and simulating last step")
+println("Reading and simulating last two steps")
 # Two additional steps
 two_steps["t_end"] = "720secs"
 cs_two_steps2 = setup_and_run(two_steps)

experiments/ClimaEarth/user_io/arg_parsing.jl

@@ -92,8 +92,7 @@ function get_coupler_args(config_dict::Dict)
 
     # Restart information
     restart_dir = config_dict["restart_dir"]
-    restart_t =
-        isnothing(config_dict["restart_t"]) ? nothing : Int64(Utilities.time_to_seconds(config_dict["restart_t"]))
+    restart_t = config_dict["restart_t"]
 
     # Diagnostics information
     use_coupler_diagnostics = config_dict["use_coupler_diagnostics"]