Simplify bst shell implementation

man/bst-artifact-checkout.1

@@ -1,4 +1,4 @@
-.TH "BST ARTIFACT CHECKOUT" "1" "2020-08-13" "" "bst artifact checkout Manual"
+.TH "BST ARTIFACT CHECKOUT" "1" "2020-10-07" "" "bst artifact checkout Manual"
 .SH NAME
 bst\-artifact\-checkout \- Checkout contents of an artifact
 .SH SYNOPSIS

man/bst-artifact-delete.1

@@ -1,4 +1,4 @@
-.TH "BST ARTIFACT DELETE" "1" "2020-08-13" "" "bst artifact delete Manual"
+.TH "BST ARTIFACT DELETE" "1" "2020-10-07" "" "bst artifact delete Manual"
 .SH NAME
 bst\-artifact\-delete \- Remove artifacts from the local cache
 .SH SYNOPSIS

man/bst-artifact-list-contents.1

@@ -1,4 +1,4 @@
-.TH "BST ARTIFACT LIST-CONTENTS" "1" "2020-08-13" "" "bst artifact list-contents Manual"
+.TH "BST ARTIFACT LIST-CONTENTS" "1" "2020-10-07" "" "bst artifact list-contents Manual"
 .SH NAME
 bst\-artifact\-list-contents \- List the contents of an artifact
 .SH SYNOPSIS

man/bst-artifact-log.1

@@ -1,4 +1,4 @@
-.TH "BST ARTIFACT LOG" "1" "2020-08-13" "" "bst artifact log Manual"
+.TH "BST ARTIFACT LOG" "1" "2020-10-07" "" "bst artifact log Manual"
 .SH NAME
 bst\-artifact\-log \- Show logs of artifacts
 .SH SYNOPSIS

man/bst-artifact-pull.1

@@ -1,4 +1,4 @@
-.TH "BST ARTIFACT PULL" "1" "2020-08-13" "" "bst artifact pull Manual"
+.TH "BST ARTIFACT PULL" "1" "2020-10-07" "" "bst artifact pull Manual"
 .SH NAME
 bst\-artifact\-pull \- Pull a built artifact
 .SH SYNOPSIS

man/bst-artifact-push.1

@@ -1,4 +1,4 @@
-.TH "BST ARTIFACT PUSH" "1" "2020-08-13" "" "bst artifact push Manual"
+.TH "BST ARTIFACT PUSH" "1" "2020-10-07" "" "bst artifact push Manual"
 .SH NAME
 bst\-artifact\-push \- Push a built artifact
 .SH SYNOPSIS

man/bst-artifact-server.1

@@ -1,4 +1,4 @@
-.TH "BST-ARTIFACT-SERVER" "1" "2020-08-13" "" "bst-artifact-server Manual"
+.TH "BST-ARTIFACT-SERVER" "1" "2020-10-07" "" "bst-artifact-server Manual"
 .SH NAME
 bst-artifact-server \- CAS Artifact Server
 .SH SYNOPSIS

man/bst-artifact-show.1

@@ -1,4 +1,4 @@
-.TH "BST ARTIFACT SHOW" "1" "2020-08-13" "" "bst artifact show Manual"
+.TH "BST ARTIFACT SHOW" "1" "2020-10-07" "" "bst artifact show Manual"
 .SH NAME
 bst\-artifact\-show \- Show the cached state of artifacts
 .SH SYNOPSIS

man/bst-artifact.1

@@ -1,4 +1,4 @@
-.TH "BST ARTIFACT" "1" "2020-08-13" "" "bst artifact Manual"
+.TH "BST ARTIFACT" "1" "2020-10-07" "" "bst artifact Manual"
 .SH NAME
 bst\-artifact \- Manipulate cached artifacts.
 .SH SYNOPSIS

man/bst-build.1

@@ -1,4 +1,4 @@
-.TH "BST BUILD" "1" "2020-08-13" "" "bst build Manual"
+.TH "BST BUILD" "1" "2020-10-07" "" "bst build Manual"
 .SH NAME
 bst\-build \- Build elements in a pipeline
 .SH SYNOPSIS

man/bst-help.1

@@ -1,4 +1,4 @@
-.TH "BST HELP" "1" "2020-08-13" "" "bst help Manual"
+.TH "BST HELP" "1" "2020-10-07" "" "bst help Manual"
 .SH NAME
 bst\-help \- Print usage information
 .SH SYNOPSIS

man/bst-init.1

@@ -1,4 +1,4 @@
-.TH "BST INIT" "1" "2020-08-13" "" "bst init Manual"
+.TH "BST INIT" "1" "2020-10-07" "" "bst init Manual"
 .SH NAME
 bst\-init \- Initialize a new BuildStream project
 .SH SYNOPSIS

man/bst-shell.1

@@ -1,4 +1,4 @@
-.TH "BST SHELL" "1" "2020-08-13" "" "bst shell Manual"
+.TH "BST SHELL" "1" "2020-10-07" "" "bst shell Manual"
 .SH NAME
 bst\-shell \- Shell into an element's sandbox environment
 .SH SYNOPSIS
@@ -36,8 +36,8 @@ Mount a file or directory into the sandbox
 \fB\-\-isolate\fP
 Create an isolated build sandbox
 .TP
-\fB\-t,\fP \-\-use\-buildtree [ask|try|always|never]
-Stage a buildtree. If `always` is set, will always fail to build if a buildtree is not available. --pull and pull-buildtrees configuration is needed if trying to query for remotely cached buildtrees.  [default: ask]
+\fB\-t,\fP \-\-use\-buildtree [try|always|never]
+Stage a buildtree. If `always` is set, will always fail to build if a buildtree is not available. --pull and pull-buildtrees configuration is needed if trying to query for remotely cached buildtrees.  [default: never]
 .TP
 \fB\-\-pull\fP
 Attempt to pull missing or incomplete artifacts

man/bst-show.1

@@ -1,4 +1,4 @@
-.TH "BST SHOW" "1" "2020-08-13" "" "bst show Manual"
+.TH "BST SHOW" "1" "2020-10-07" "" "bst show Manual"
 .SH NAME
 bst\-show \- Show elements in the pipeline
 .SH SYNOPSIS

man/bst-source-checkout.1

@@ -1,4 +1,4 @@
-.TH "BST SOURCE CHECKOUT" "1" "2020-08-13" "" "bst source checkout Manual"
+.TH "BST SOURCE CHECKOUT" "1" "2020-10-07" "" "bst source checkout Manual"
 .SH NAME
 bst\-source\-checkout \- Checkout sources of an element
 .SH SYNOPSIS

man/bst-source-fetch.1

@@ -1,4 +1,4 @@
-.TH "BST SOURCE FETCH" "1" "2020-08-13" "" "bst source fetch Manual"
+.TH "BST SOURCE FETCH" "1" "2020-10-07" "" "bst source fetch Manual"
 .SH NAME
 bst\-source\-fetch \- Fetch sources in a pipeline
 .SH SYNOPSIS

man/bst-source-push.1

@@ -1,4 +1,4 @@
-.TH "BST SOURCE PUSH" "1" "2020-08-13" "" "bst source push Manual"
+.TH "BST SOURCE PUSH" "1" "2020-10-07" "" "bst source push Manual"
 .SH NAME
 bst\-source\-push \- Push sources in a pipeline
 .SH SYNOPSIS

man/bst-source-track.1

@@ -1,4 +1,4 @@
-.TH "BST SOURCE TRACK" "1" "2020-08-13" "" "bst source track Manual"
+.TH "BST SOURCE TRACK" "1" "2020-10-07" "" "bst source track Manual"
 .SH NAME
 bst\-source\-track \- Track new source references
 .SH SYNOPSIS

man/bst-source.1

@@ -1,4 +1,4 @@
-.TH "BST SOURCE" "1" "2020-08-13" "" "bst source Manual"
+.TH "BST SOURCE" "1" "2020-10-07" "" "bst source Manual"
 .SH NAME
 bst\-source \- Manipulate sources for an element
 .SH SYNOPSIS

man/bst-workspace-close.1

@@ -1,4 +1,4 @@
-.TH "BST WORKSPACE CLOSE" "1" "2020-08-13" "" "bst workspace close Manual"
+.TH "BST WORKSPACE CLOSE" "1" "2020-10-07" "" "bst workspace close Manual"
 .SH NAME
 bst\-workspace\-close \- Close workspaces
 .SH SYNOPSIS

man/bst-workspace-list.1

@@ -1,4 +1,4 @@
-.TH "BST WORKSPACE LIST" "1" "2020-08-13" "" "bst workspace list Manual"
+.TH "BST WORKSPACE LIST" "1" "2020-10-07" "" "bst workspace list Manual"
 .SH NAME
 bst\-workspace\-list \- List open workspaces
 .SH SYNOPSIS

man/bst-workspace-open.1

@@ -1,4 +1,4 @@
-.TH "BST WORKSPACE OPEN" "1" "2020-08-13" "" "bst workspace open Manual"
+.TH "BST WORKSPACE OPEN" "1" "2020-10-07" "" "bst workspace open Manual"
 .SH NAME
 bst\-workspace\-open \- Open a new workspace
 .SH SYNOPSIS

man/bst-workspace-reset.1

@@ -1,4 +1,4 @@
-.TH "BST WORKSPACE RESET" "1" "2020-08-13" "" "bst workspace reset Manual"
+.TH "BST WORKSPACE RESET" "1" "2020-10-07" "" "bst workspace reset Manual"
 .SH NAME
 bst\-workspace\-reset \- Reset a workspace to its original state
 .SH SYNOPSIS

man/bst-workspace.1

@@ -1,4 +1,4 @@
-.TH "BST WORKSPACE" "1" "2020-08-13" "" "bst workspace Manual"
+.TH "BST WORKSPACE" "1" "2020-10-07" "" "bst workspace Manual"
 .SH NAME
 bst\-workspace \- Manipulate developer workspaces
 .SH SYNOPSIS

man/bst.1

@@ -1,4 +1,4 @@
-.TH "BST" "1" "2020-08-13" "" "bst Manual"
+.TH "BST" "1" "2020-10-07" "" "bst Manual"
 .SH NAME
 bst \- Build and manipulate BuildStream projects...
 .SH SYNOPSIS

src/buildstream/_frontend/app.py

@@ -446,15 +446,16 @@ def init_project(
     # if they are available in the execution context.
     #
     # Args:
-    #    element_name (str): The element's full name
-    #    element_key (tuple): The element's display key
+    #    element (Element): The element
     #
     # Returns:
     #    (str): The formatted prompt to display in the shell
     #
-    def shell_prompt(self, element_name, element_key):
+    def shell_prompt(self, element):
 
-        _, key, dim = element_key
+        element_name = element._get_full_name()
+
+        _, key, dim = element._get_display_key()
 
         if self.colors:
             prompt = (
@@ -703,10 +704,14 @@ def _handle_failure(self, element, task, failure):
                 if choice == "shell":
                     click.echo("\nDropping into an interactive shell in the failed build sandbox\n", err=True)
                     try:
-                        unique_id, element_key = element
-                        prompt = self.shell_prompt(full_name, element_key)
+                        unique_id, _ = element
                         self.stream.shell(
-                            None, _Scope.BUILD, prompt, isolate=True, usebuildtree="always", unique_id=unique_id
+                            None,
+                            _Scope.BUILD,
+                            self.shell_prompt,
+                            isolate=True,
+                            usebuildtree="always",
+                            unique_id=unique_id,
                         )
                     except BstError as e:
                         click.echo("Error while attempting to create interactive shell: {}".format(e), err=True)

src/buildstream/_frontend/cli.py

@@ -578,8 +578,8 @@ def show(app, elements, deps, except_, order, format_):
     "--use-buildtree",
     "-t",
     "cli_buildtree",
-    type=click.Choice(["ask", "try", "always", "never"]),
-    default="ask",
+    type=click.Choice(["try", "always", "never"]),
+    default="never",
     show_default=True,
     help=(
         "Stage a buildtree. If `always` is set, will always fail to "
@@ -617,116 +617,32 @@ def shell(app, element, mount, isolate, build_, cli_buildtree, pull_, command):
     from ..element import _Scope
     from .._project import HostMount
 
-    scope = _Scope.BUILD if build_ else _Scope.RUN
+    # Buildtree can only be used with build shells
+    if cli_buildtree != "never":
+        build_ = True
+    else:
+        cli_buildtree = None
 
-    # We may need to fetch dependency artifacts if we're pulling the artifact
-    selection = _PipelineSelection.ALL if pull_ else _PipelineSelection.NONE
-    use_buildtree = None
+    scope = _Scope.BUILD if build_ else _Scope.RUN
 
     with app.initialized():
         if not element:
             element = app.project.get_default_target()
             if not element:
                 raise AppError('Missing argument "ELEMENT".')
 
-        elements = app.stream.load_selection((element,), selection=selection, use_artifact_config=True)
-
-        # last one will be the element we want to stage, previous ones are
-        # elements to try and pull
-        element = elements[-1]
-        pull_dependencies = elements[:-1] if pull_ else None
-
-        element_name = element._get_full_name()
-        element_key = element._get_display_key()
-
-        prompt = app.shell_prompt(element_name, element_key)
         mounts = [HostMount(path, host_path) for host_path, path in mount]
 
-        artifact_is_cached = element._cached()
-        buildtree_is_cached = element._cached_buildtree()
-        buildtree_exists = element._buildtree_exists()
-        can_attempt_pull = app.context.pull_buildtrees and pull_
-
-        if cli_buildtree in ("always", "try"):
-            if buildtree_is_cached:
-                use_buildtree = cli_buildtree
-            # If element is already cached, we can check the proto to see if the buildtree existed
-            elif artifact_is_cached:
-                if not buildtree_exists:
-                    if cli_buildtree == "always":
-                        # Exit early if it won't be possible to even fetch a buildtree with always option
-                        raise AppError("Artifact was created without buildtree, unable to launch shell with it")
-                    click.echo(
-                        "WARNING: Artifact created without buildtree, shell will be loaded without it", err=True
-                    )
-                elif can_attempt_pull:
-                    use_buildtree = cli_buildtree
-                    click.echo(
-                        "WARNING: buildtree is not cached locally but did exist, will attempt to pull from available remotes",
-                        err=True,
-                    )
-                else:
-                    if cli_buildtree == "always":
-                        # Exit early if it won't be possible to perform a fetch as pull semantics aren't present
-                        raise AppError(
-                            "Artifact has a buildtree but it isn't cached. Can be retried with --pull and pull-buildtrees configured"
-                        )
-                    click.echo("WARNING: buildtree is not cached locally, shell will be loaded without it", err=True)
-            # If element isn't cached at all, we can't check the proto to see if it existed so can't exit early
-            elif can_attempt_pull:
-                use_buildtree = cli_buildtree
-                if use_buildtree == "always":
-                    click.echo(
-                        "WARNING: Element is not cached so buildtree status unknown, will attempt to pull from available remotes",
-                        err=True,
-                    )
-            else:
-                if cli_buildtree == "always":
-                    # Exit early as there is no buildtree locally & can_attempt_pull is False
-                    raise AppError(
-                        "Artifact not cached locally. Can be retried with --pull and pull-buildtrees configured"
-                    )
-                click.echo("WARNING: buildtree is not cached locally, shell will be loaded without it", err=True)
-        else:
-            # If the value has defaulted to ask and in non interactive mode, don't consider the buildtree, this
-            # being the default behaviour of the command
-            if app.interactive and cli_buildtree == "ask":
-                if buildtree_is_cached and bool(click.confirm("Do you want to use the cached buildtree?")):
-                    use_buildtree = "always"
-                elif can_attempt_pull:
-                    # If buildtree not cached, check if it's worth presenting the user a dialogue
-                    message = None
-                    if artifact_is_cached:
-                        if buildtree_exists:
-                            message = "Buildtree not cached but can be pulled if in available remotes, do you want to use it?"
-                    else:
-                        message = "Element is not cached so buildtree status unknown, do you want to pull and use it?"
-                    if message:
-                        try:
-                            choice = click.prompt(
-                                message, type=click.Choice(["try", "always", "never"]), err=True, show_choices=True,
-                            )
-                        except click.Abort:
-                            click.echo("Aborting", err=True)
-                            sys.exit(-1)
-
-                        if choice != "never":
-                            use_buildtree = choice
-
-        # Raise warning if the element is cached in a failed state
-        if use_buildtree and element._cached_failure():
-            click.echo("WARNING: using a buildtree from a failed build.", err=True)
-
         try:
             exitcode = app.stream.shell(
                 element,
                 scope,
-                prompt,
+                app.shell_prompt,
                 mounts=mounts,
                 isolate=isolate,
                 command=command,
-                usebuildtree=use_buildtree,
-                pull_dependencies=pull_dependencies,
+                usebuildtree=cli_buildtree,
+                pull_=pull_,
             )
         except BstError as e:
             raise AppError("Error launching shell: {}".format(e), detail=e.detail) from e