depfile: improve tab completion (#33773)

This PR allows you to do:

```
spack env create -d .
spack -e . add python
spack -e . concretize
spack -e . env depfile -o Makefile

make in<tab>              # -> install
make install-<tab>        # -> install-deps/
make install-deps/py<tab> # -> install-deps/python-x.y.z-hash
make install/zl<tab>      # -> install/zlib-x.y.z-hash

make SP<tab>              # -> make SPACK
make SPACK_<tab>          # -> make SPACK_INSTALL_FLAGS=
```

1 files changed, 17 insertions, 6 deletions

diff --git a/share/spack/templates/depfile/Makefile b/share/spack/templates/depfile/Makefile
index dc0aeb79ea..4ff7fff0a3 100644
--- a/share/spack/templates/depfile/Makefile
+++ b/share/spack/templates/depfile/Makefile
@@ -1,4 +1,5 @@
 SPACK ?= spack
+SPACK_INSTALL_FLAGS ?=
 
 .PHONY: {{ all_target }} {{ clean_target }}
 
@@ -10,27 +11,37 @@ SPACK ?= spack
 {{ dirs_target }}:
 	@mkdir -p {{ install_target }} {{ install_deps_target }}
 
+{% if phony_convenience_targets %}
+.PHONY: {{ phony_convenience_targets }}
+{% endif %}
+
 # The spack install commands are of the form:
 # spack -e my_env --no-add --only=package --only=concrete /hash
 # This is an involved way of expressing that Spack should only install
 # an individual concrete spec from the environment without deps.
-{{ install_target }}/%: {{ install_deps_target }}/% | {{ dirs_target }}
-	{{ jobserver_support }}$(SPACK) -e '{{ environment }}' install $(SPACK_BUILDCACHE_FLAG) $(SPACK_INSTALL_FLAGS) --only-concrete --only=package --no-add /$(notdir $@) # $(SPEC)
+{{ install_target }}/%: | {{ dirs_target }}
+	{{ jobserver_support }}$(SPACK) -e '{{ environment }}' install $(SPACK_BUILDCACHE_FLAG) $(SPACK_INSTALL_FLAGS) --only-concrete --only=package --no-add /$(HASH) # $(SPEC)
 	@touch $@
 
 {{ install_deps_target }}/%: | {{ dirs_target }}
 	@touch $@
 
 # Set a human-readable SPEC variable for each target that has a hash
-{% for (parent, name, build_cache, _) in adjacency_list -%}
+{% for (parent, _, hash, name, build_cache) in adjacency_list -%}
+{{ any_hash_target }}/{{ parent }}: HASH = {{ hash }}
 {{ any_hash_target }}/{{ parent }}: SPEC = {{ name }}
 {{ any_hash_target }}/{{ parent }}: SPACK_BUILDCACHE_FLAG = {{ build_cache }}
 {% endfor %}
 
 # The Spack DAG expressed in targets:
-{% for (parent, _, _, prereqs) in adjacency_list -%}
-{{ install_deps_target }}/{{ parent }}: {{prereqs}}
+{% for (parent, prereqs, _, _, _) in adjacency_list -%}
+{{ install_target }}/{{ parent }}: {{ install_deps_target }}/{{ parent }}
+{{ install_deps_target }}/{{ parent }}: {{ prereqs }}
+{% if phony_convenience_targets %}
+install/{{ parent }}: {{ install_target }}/{{ parent }}
+install-deps/{{ parent }}: {{ install_deps_target }}/{{ parent }}
+{% endif %}
 {% endfor %}
 
 {{ clean_target }}:
-	rm -rf {{ env_target }} {{ cleanable_targets }}
+	rm -rf {{ env_target }} {{ all_install_related_targets }}