Remove petrify and unpetrify commands

We don't use this any more, and instead prefer to always keep
definitions.git petrified, and update the refs ourselves.

branch-from-image still uses some of the remaining petrify code.

15 files changed, 1 insertions, 698 deletions

diff --git a/doc/branching-merging-systems.mdwn b/doc/branching-merging-systems.mdwn
index c2e24d77..3bc19aab 100644
--- a/doc/branching-merging-systems.mdwn
+++ b/doc/branching-merging-systems.mdwn
@@ -129,7 +129,7 @@ Also, clone the `morphs` git repository inside the system branch
 directory.
 
     cd ~/baserock/liw/foo/morphs
-    morph petrify base-system.morph devel-system.morph
+    edit base-system.morph devel-system.morph
     git commit -a
     
 Modify the specified morphologies (or the stratum morphologies they
@@ -225,36 +225,6 @@ it to exist instead.
 * Run `git checkout BRANCH` in the `morphs` repository.
 
 
-Implementation: `morph petrify`
---------------
-
-Usage:
-
-    morph petrify [MORPH]...
-    morph petrify --petrify-from-system FILE
-    
-This needs to be run in the `morphs` git repository in a system branch.
-
-In the first form:
-
-* read each of the given morphologies; if the morphology is a system one, 
-  follow references to stratum morphologies and process those instead
-* in each stratum morphology, replace a reference to a chunk with the
-  absolute SHA-1: if the original reference was, say, `baserock/morph`,
-  get the SHA-1 of the current tip commit in that branch and replace
-  the reference in the morphology
-  
-In the second form:
-
-* extract the system and stratum morphologies used in the system image file;
-  these are in a petrified form already
-* copy the morphologies to the current working directory, overwriting the
-  files from git
-
-In either case, the results need to be committed (with normal git commands)
-by the user.
-
-
 Implementation: `morph edit`
 --------------
 
diff --git a/morphlib/morphset.py b/morphlib/morphset.py
index 590ac51e..fa525973 100644
--- a/morphlib/morphset.py
+++ b/morphlib/morphset.py
@@ -243,17 +243,3 @@ class MorphologySet(object):
             return True
 
         self.traverse_specs(process_chunk_spec, wanted_chunk_spec)
-
-    def unpetrify_all(self):
-        '''If a spec is petrified, unpetrify it.
-
-        '''
-
-        def wanted_spec(m, kind, spec):
-            return ('unpetrify-ref' in spec and
-                    morphlib.git.is_valid_sha1(spec.get('ref')))
-        def process_spec(m, kind, spec):
-            spec['ref'] = spec.pop('unpetrify-ref')
-            return True
-
-        self.traverse_specs(process_spec, wanted_spec)
diff --git a/morphlib/morphset_tests.py b/morphlib/morphset_tests.py
index 8679c64a..af1333d8 100644
--- a/morphlib/morphset_tests.py
+++ b/morphlib/morphset_tests.py
@@ -200,18 +200,3 @@ class MorphologySetTests(unittest.TestCase):
                     'unpetrify-ref': 'master',
                 }
             ])
-
-    def test_unpetrify_all(self):
-        self.morphs.add_morphology(self.system)
-        self.morphs.add_morphology(self.stratum)
-        self.morphs.petrify_chunks({('test:foo-chunk', 'master'): '0'*40})
-        self.morphs.unpetrify_all()
-        self.assertEqual(
-            self.stratum['chunks'],
-            [
-                {
-                    'repo': 'test:foo-chunk',
-                    'ref': 'master',
-                    'morph': 'foo-chunk',
-                }
-            ])
diff --git a/morphlib/plugins/branch_and_merge_plugin.py b/morphlib/plugins/branch_and_merge_plugin.py
index a66098b8..9450c67b 100644
--- a/morphlib/plugins/branch_and_merge_plugin.py
+++ b/morphlib/plugins/branch_and_merge_plugin.py
@@ -38,10 +38,6 @@ class BranchAndMergePlugin(cliapp.Plugin):
         self.app.add_subcommand(
             'edit', self.edit, arg_synopsis='SYSTEM STRATUM [CHUNK]')
         self.app.add_subcommand(
-            'petrify', self.petrify, arg_synopsis='')
-        self.app.add_subcommand(
-            'unpetrify', self.unpetrify, arg_synopsis='')
-        self.app.add_subcommand(
             'show-system-branch', self.show_system_branch, arg_synopsis='')
         self.app.add_subcommand(
             'show-branch-root', self.show_branch_root, arg_synopsis='')
@@ -486,100 +482,6 @@ class BranchAndMergePlugin(cliapp.Plugin):
             morphs.add_morphology(morph)
         return morphs
 
-    def petrify(self, args):
-        '''Convert all chunk refs in a system branch to be fixed SHA1s.
-
-        This modifies all git commit references in system and stratum
-        morphologies, in the current system branch, to be fixed SHA
-        commit identifiers, rather than symbolic branch or tag names.
-        This is useful for making sure none of the components in a system
-        branch change accidentally.
-
-        Consider the following scenario:
-
-        * The `master` system branch refers to `gcc` using the
-          `baserock/morph` ref. This is appropriate, since the main line
-          of development should use the latest curated code.
-
-        * You create a system branch to prepare for a release, called
-          `TROVE_ID/release/2.0`. The reference to `gcc` is still
-          `baserock/morph`.
-
-        * You test everything, and make a release. You deploy the release
-          images onto devices, which get shipped to your customers.
-
-        * A new version GCC is committed to the `baserock/morph` branch.
-
-        * Your release branch suddenly uses a new compiler, which may
-          or may not work for your particular system at that release.
-
-        To avoid this, you need to _petrify_ all git references
-        so that they do not change accidentally. If you've tested
-        your release with the GCC release that is stored in commit
-        `94c50665324a7aeb32f3096393ec54b2e63bfb28`, then you should
-        continue to use that version of GCC, regardless of what might
-        happen in the master system branch. If, and only if, you decide
-        that a new compiler would be good for your release should you
-        include it in your release branch. This way, only the things
-        that you change intentionally change in your release branch.
-
-        '''
-
-        if args:
-            raise cliapp.AppException('morph petrify takes no arguments')
-
-        ws = morphlib.workspace.open('.')
-        sb = morphlib.sysbranchdir.open_from_within('.')
-        loader = morphlib.morphloader.MorphologyLoader()
-        lrc, rrc = morphlib.util.new_repo_caches(self.app)
-        update_repos = not self.app.settings['no-git-update']
-
-        morphs = self._load_all_sysbranch_morphologies(sb, loader)
-
-        #TODO: Stop using app.resolve_ref
-        def resolve_refs(morphs):
-            for repo, ref in morphs.list_refs():
-                # You can't resolve null refs, so don't attempt to.
-                if repo is None or ref is None:
-                    continue
-                # TODO: Handle refs that are only in workspace in general
-                if (repo == sb.root_repository_url
-                    and ref == sb.system_branch_name):
-                    continue
-                commit_sha1, tree_sha1 = self.app.resolve_ref(
-                    lrc, rrc, repo, ref, update=update_repos)
-                yield ((repo, ref), commit_sha1)
-
-        morphs.repoint_refs(sb.root_repository_url,
-                            sb.system_branch_name)
-
-        morphs.petrify_chunks(dict(resolve_refs(morphs)))
-
-        # Write morphologies back out again.
-        self._save_dirty_morphologies(loader, sb, morphs.morphologies)
-
-    def unpetrify(self, args):
-        '''Reverse the process of petrification.
-
-        This undoes the changes `morph petrify` did.
-
-        '''
-
-        if args:
-            raise cliapp.AppException('morph petrify takes no arguments')
-
-        ws = morphlib.workspace.open('.')
-        sb = morphlib.sysbranchdir.open_from_within('.')
-        loader = morphlib.morphloader.MorphologyLoader()
-
-        morphs = self._load_all_sysbranch_morphologies(sb, loader)
-
-        # Restore the ref for each stratum and chunk
-        morphs.unpetrify_all()
-
-        # Write morphologies back out again.
-        self._save_dirty_morphologies(loader, sb, morphs.morphologies)
-
     def status(self, args):
         '''Show information about the current system branch or workspace
 
diff --git a/tests.as-root/unimportant-morphology-contents-do-not-change-cache-keys.script b/tests.as-root/unimportant-morphology-contents-do-not-change-cache-keys.script
deleted file mode 100755
index a540cdee..00000000
--- a/tests.as-root/unimportant-morphology-contents-do-not-change-cache-keys.script
+++ /dev/null
@@ -1,45 +0,0 @@
-#!/bin/bash
-#
-# Copyright (C) 2012-2014  Codethink Limited
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; version 2 of the License.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write to the Free Software Foundation, Inc.,
-# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-
-## Some contents of morphologies (description, build-depends, chunks)
-## should not change the cache keys of those morphs because they are
-## either already considered (build-depends and chunks) or do not affect
-## building (description). This test checks that changes to these parts
-## of a morphology do not force rebuilds.
-
-# FIXME: This seems to break because the new "morph edit" makes correct
-# changes to build-dependencies, which breaks the old "morph build".
-# Disable test now, re-enable it after "morph build" is fixed. --liw
-exit 0
-
-set -eu
-
-source "$SRCDIR/tests.as-root/setup-build"
-
-# Build once.
-cd "$DATADIR/workspace"
-"$SRCDIR/scripts/test-morph" build linux-system
-ARTIFACT_COUNT="$(ls "$DATADIR/cache/artifacts" | wc -l)"
-
-# Petrify the refs, so the morphologies will be different
-(set -e && cd branch1/test/morphs && git push --quiet origin HEAD)
-(set -e && cd branch1/test/kernel-repo && git push --quiet origin HEAD)
-"$SRCDIR/scripts/test-morph" petrify
-
-# Build with the petrified morphologies.
-"$SRCDIR/scripts/test-morph" build linux-system
-[ "$ARTIFACT_COUNT" -eq $(ls "$DATADIR/cache/artifacts" | wc -l) ]
diff --git a/tests.branching.disabled/workflow-petrify.script b/tests.branching.disabled/workflow-petrify.script
deleted file mode 100755
index 3c561d5b..00000000
--- a/tests.branching.disabled/workflow-petrify.script
+++ /dev/null
@@ -1,67 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) 2012-2014  Codethink Limited
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; version 2 of the License.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write to the Free Software Foundation, Inc.,
-# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-
-
-## Do a complete workflow test, with strata outside the main morphologies
-## repository.
-
-set -eu
-
-. "$SRCDIR/scripts/setup-3rd-party-strata"
-
-cd "$DATADIR/workspace"
-"$SRCDIR/scripts/test-morph" branch test:morphs test/petrify
-
-cd test/petrify
-"$SRCDIR/scripts/test-morph" petrify
-
-echo "test/petrify after petrifying:"
-cat test:morphs/hello-system.morph
-cat test:external-strata/stratum2.morph
-cat test:external-strata/stratum3.morph
-
-"$SRCDIR/scripts/test-morph" edit hello
-
-echo
-echo "test/petrify after editing a chunk:"
-cat test:morphs/hello-system.morph
-cat test:external-strata/stratum2.morph
-cat test:external-strata/stratum3.morph
-
-# me/readme-fixes in test:stratum2-hello should be 'master', but
-# that's the only ref upstream so we can infer that it is if we got here
-
-cd test:morphs
-git commit --quiet --all -m "Petrify branch test/petrify"
-git push --quiet origin test/petrify
-cd ../test:external-strata
-git commit --quiet --all -m "Petrify branch test/petrify"
-git push --quiet origin test/petrify
-
-# unpetrify is easy enough. Let's try unpetrifying a different branch that
-# was forked off the original while it was petrified, instead.
-cd "$DATADIR/workspace"
-"$SRCDIR/scripts/test-morph" branch test:morphs test/unpetrify test/petrify
-
-cd test/unpetrify
-"$SRCDIR/scripts/test-morph" unpetrify
-
-echo
-echo "test/unpetrify after unpetrifying:"
-cat test:morphs/hello-system.morph
-cat test:external-strata/stratum2.morph
-cat test:external-strata/stratum3.morph
diff --git a/tests.branching.disabled/workflow-petrify.stdout b/tests.branching.disabled/workflow-petrify.stdout
deleted file mode 100644
index a0ce82f4..00000000
--- a/tests.branching.disabled/workflow-petrify.stdout
+++ /dev/null
@@ -1,152 +0,0 @@
-test/petrify after petrifying:
-{
-    "name": "hello-system",
-    "kind": "system",
-    "arch": "x86_64",
-    "strata": [
-        {
-            "morph": "hello-stratum",
-            "repo": "test:morphs",
-            "ref": "test/petrify"
-        },
-        {
-            "morph": "stratum2",
-            "repo": "test:external-strata",
-            "ref": "test/petrify"
-        },
-        {
-            "morph": "stratum3",
-            "repo": "test:external-strata",
-            "ref": "test/petrify"
-        }
-    ]
-}
-{
-    "name": "stratum2",
-    "kind": "stratum",
-    "chunks": [
-        {
-            "name": "hello",
-            "repo": "test:stratum2-hello",
-            "ref": "f4730636e429149bb923fa16be3aa9802d484b23",
-            "build-mode": "test",
-            "build-depends": [],
-            "unpetrify-ref": "master"
-        }
-    ]
-}
-{
-    "name": "stratum3",
-    "kind": "stratum",
-    "chunks": [
-        {
-            "name": "hello",
-            "repo": "test:stratum3-hello",
-            "ref": "f4730636e429149bb923fa16be3aa9802d484b23",
-            "build-mode": "test",
-            "build-depends": [],
-            "unpetrify-ref": "master"
-        }
-    ]
-}
-
-test/petrify after editing a chunk:
-{
-    "name": "hello-system",
-    "kind": "system",
-    "arch": "x86_64",
-    "strata": [
-        {
-            "morph": "hello-stratum",
-            "repo": "test:morphs",
-            "ref": "test/petrify"
-        },
-        {
-            "morph": "stratum2",
-            "repo": "test:external-strata",
-            "ref": "test/petrify"
-        },
-        {
-            "morph": "stratum3",
-            "repo": "test:external-strata",
-            "ref": "test/petrify"
-        }
-    ]
-}
-{
-    "name": "stratum2",
-    "kind": "stratum",
-    "chunks": [
-        {
-            "name": "hello",
-            "repo": "test:stratum2-hello",
-            "ref": "test/petrify",
-            "build-mode": "test",
-            "build-depends": []
-        }
-    ]
-}
-{
-    "name": "stratum3",
-    "kind": "stratum",
-    "chunks": [
-        {
-            "name": "hello",
-            "repo": "test:stratum3-hello",
-            "ref": "f4730636e429149bb923fa16be3aa9802d484b23",
-            "build-mode": "test",
-            "build-depends": [],
-            "unpetrify-ref": "master"
-        }
-    ]
-}
-
-test/unpetrify after unpetrifying:
-{
-    "name": "hello-system",
-    "kind": "system",
-    "arch": "x86_64",
-    "strata": [
-        {
-            "morph": "hello-stratum",
-            "repo": "test:morphs",
-            "ref": "test/unpetrify"
-        },
-        {
-            "morph": "stratum2",
-            "repo": "test:external-strata",
-            "ref": "test/unpetrify"
-        },
-        {
-            "morph": "stratum3",
-            "repo": "test:external-strata",
-            "ref": "test/unpetrify"
-        }
-    ]
-}
-{
-    "name": "stratum2",
-    "kind": "stratum",
-    "chunks": [
-        {
-            "name": "hello",
-            "repo": "test:stratum2-hello",
-            "ref": "test/petrify",
-            "build-mode": "test",
-            "build-depends": []
-        }
-    ]
-}
-{
-    "name": "stratum3",
-    "kind": "stratum",
-    "chunks": [
-        {
-            "name": "hello",
-            "repo": "test:stratum3-hello",
-            "ref": "master",
-            "build-mode": "test",
-            "build-depends": []
-        }
-    ]
-}
diff --git a/tests.branching/ambiguous-refs.script b/tests.branching/ambiguous-refs.script
deleted file mode 100755
index aeec61a1..00000000
--- a/tests.branching/ambiguous-refs.script
+++ /dev/null
@@ -1,46 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) 2012-2014  Codethink Limited
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; version 2 of the License.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write to the Free Software Foundation, Inc.,
-# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-
-
-## Guard against a bug that occurs if 'git show-ref' is used to resolve refs
-## instead of 'git rev-parse --verify': show-ref returns a list of partial
-## matches sorted alphabetically, so any code using it may resolve refs
-## incorrectly.
-
-set -eu
-
-. "$SRCDIR/scripts/fix-committer-info"
-
-cd "$DATADIR/morphs"
-git mv hello-stratum.morph goodbye-stratum.morph
-sed -e '/morph: hello-stratum/s/hello-stratum/goodbye-stratum/' \
-    -i hello-system.morph
-
-git commit --quiet -am "Rename hello-system"
-
-cd "$DATADIR/workspace"
-"$SRCDIR/scripts/test-morph" init
-"$SRCDIR/scripts/test-morph" branch test:morphs release
-
-# Create an extra ref to confuse any users of git show-ref
-cd release/test/morphs
-git checkout --quiet -b alpha/master HEAD~1
-git checkout --quiet release
-
-# The petrify will fail if we resolved 'master' as 'alpha/master' by mistake.
-cd "$DATADIR/workspace/release/test/morphs"
-"$SRCDIR/scripts/test-morph" petrify
diff --git a/tests.branching/build-after-petrify.script b/tests.branching/build-after-petrify.script
deleted file mode 100755
index d3b75f07..00000000
--- a/tests.branching/build-after-petrify.script
+++ /dev/null
@@ -1,31 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) 2013  Codethink Limited
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; version 2 of the License.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write to the Free Software Foundation, Inc.,
-# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-
-
-## Verify systems can be built after "morph petrify"
-
-set -eu
-
-. "$SRCDIR/tests.branching/setup-second-chunk"
-
-cd "$DATADIR/workspace"
-"$SRCDIR/scripts/test-morph" init
-"$SRCDIR/scripts/test-morph" branch test:morphs test/build-petrify master
-
-"$SRCDIR/scripts/test-morph" petrify
-
-"$SRCDIR/scripts/test-morph" build hello-system
diff --git a/tests.branching/petrify-no-double-petrify.script b/tests.branching/petrify-no-double-petrify.script
deleted file mode 100755
index 3c9185dc..00000000
--- a/tests.branching/petrify-no-double-petrify.script
+++ /dev/null
@@ -1,34 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) 2012-2014  Codethink Limited
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; version 2 of the License.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write to the Free Software Foundation, Inc.,
-# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-
-
-## It should be impossible to lose the original refs, or we risk making
-## unpetrify impossible.
-
-set -eu
-
-cd "$DATADIR/workspace"
-"$SRCDIR/scripts/test-morph" init
-"$SRCDIR/scripts/test-morph" branch test:morphs test/petrify
-
-cd test/petrify/test/morphs
-git push --quiet origin HEAD
-"$SRCDIR/scripts/test-morph" petrify
-"$SRCDIR/scripts/test-morph" petrify
-"$SRCDIR/scripts/test-morph" petrify
-
-cat hello-stratum.morph
diff --git a/tests.branching/petrify-no-double-petrify.stdout b/tests.branching/petrify-no-double-petrify.stdout
deleted file mode 100644
index 50da61ba..00000000
--- a/tests.branching/petrify-no-double-petrify.stdout
+++ /dev/null
@@ -1,9 +0,0 @@
-name: hello-stratum
-kind: stratum
-chunks:
-- name: hello
-  repo: test:hello
-  ref: 293fa0b08f0382c63181c36b6efa602876aa8c87
-  unpetrify-ref: master
-  build-depends: []
-  build-mode: test
diff --git a/tests.branching/petrify.script b/tests.branching/petrify.script
deleted file mode 100755
index f8e7c1e9..00000000
--- a/tests.branching/petrify.script
+++ /dev/null
@@ -1,42 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) 2012-2014  Codethink Limited
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; version 2 of the License.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write to the Free Software Foundation, Inc.,
-# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-
-
-## Verify "morph petrify", and ensure it doesn't petrify chunks that have
-## already been edited.
-
-set -eu
-
-. "$SRCDIR/tests.branching/setup-second-chunk"
-
-cd "$DATADIR/workspace"
-"$SRCDIR/scripts/test-morph" init
-"$SRCDIR/scripts/test-morph" branch test:morphs test/petrify master
-
-cd test/petrify/test/morphs
-git push --quiet origin HEAD
-"$SRCDIR/scripts/test-morph" edit goodbye
-(cd ../goodbye && git push --quiet origin HEAD)
-
-"$SRCDIR/scripts/test-morph" petrify
-echo "Petrified:"
-cat hello-stratum.morph
-
-"$SRCDIR/scripts/test-morph" unpetrify
-echo
-echo "Unpetrified:"
-cat hello-stratum.morph
diff --git a/tests.branching/petrify.stdout b/tests.branching/petrify.stdout
deleted file mode 100644
index f9f35342..00000000
--- a/tests.branching/petrify.stdout
+++ /dev/null
@@ -1,31 +0,0 @@
-Petrified:
-name: hello-stratum
-kind: stratum
-chunks:
-- name: hello
-  repo: test:hello
-  ref: 293fa0b08f0382c63181c36b6efa602876aa8c87
-  unpetrify-ref: master
-  build-depends: []
-  build-mode: test
-- name: goodbye
-  repo: test:goodbye
-  ref: 717c4a523fb5a94ca2f0a61e665fbc2da6a1f6ac
-  unpetrify-ref: test/petrify
-  build-depends: []
-  build-mode: test
-
-Unpetrified:
-name: hello-stratum
-kind: stratum
-chunks:
-- name: hello
-  repo: test:hello
-  ref: master
-  build-depends: []
-  build-mode: test
-- name: goodbye
-  repo: test:goodbye
-  ref: test/petrify
-  build-depends: []
-  build-mode: test
diff --git a/yarns/branches-workspaces.yarn b/yarns/branches-workspaces.yarn
index 642beadd..995a9450 100644
--- a/yarns/branches-workspaces.yarn
+++ b/yarns/branches-workspaces.yarn
@@ -406,41 +406,6 @@ branch checkout.
     THEN  morph ran command in test/morphs in foo
     AND   morph ran command in test/test-chunk in foo
 
-Explicit petrification
-----------------------
-
-We petrify branches explicitly (though this may later change so that
-`morph branch` does it automatically). To test this, we create a branch,
-petrify it, and verify that every ref looks like a SHA1. We then
-unpetrify and verify that we have all the same refs as before.
-
-    SCENARIO    morph petrifies and unpetrifies
-    GIVEN       a workspace
-    AND         a git server
-    WHEN        the user creates a system branch called foo
-    AND         the user pushes the system branch called foo to the git server
-    AND         remembering all refs in foo
-    AND         petrifying foo
-    THEN        foo is petrified
-
-Petrifying a morphology should not cause it to start having repo or ref
-fields when referring to strata, when it didn't before.
-
-    AND  in branch foo, system systems/test-system.morph refers to test-stratum without repo
-    AND  in branch foo, system systems/test-system.morph refers to test-stratum without ref
-
-Unpetrify must put the morphologies back in the same logical state they
-were in before.
-
-    WHEN        unpetrifying foo
-    THEN        foo refs are as remembered
-
-Unpetrifying a morphology should not cause it to start having repo or
-ref fields when referring to strata, when it didn't before.
-
-    AND  in branch foo, system systems/test-system.morph refers to test-stratum without repo
-    AND  in branch foo, system systems/test-system.morph refers to test-stratum without ref
-
 Generating a manifest works
 
     SCENARIO    morph generates a manifest
diff --git a/yarns/implementations.yarn b/yarns/implementations.yarn
index a28fda54..24f67a1b 100644
--- a/yarns/implementations.yarn
+++ b/yarns/implementations.yarn
@@ -518,54 +518,6 @@ Running shell command in each checked out repository:
     grep -Fx "$MATCH_1" "$DATADIR/morph.stdout"
     grep -Fx "$DATADIR/workspace/$MATCH_2/$MATCH_1" "$DATADIR/morph.stdout"
 
-Petrification and unpetrification:
-
-    IMPLEMENTS WHEN remembering all refs in (\S+)
-    cd "$DATADIR/workspace/$MATCH_1/test/morphs"
-    list_refs $(find . -type f) > "$DATADIR/refs.remembered"
-
-    IMPLEMENTS THEN (\S+) refs are as remembered
-    cd "$DATADIR/workspace/$MATCH_1/test/morphs"
-
-    # FIXME: petrify/unpetrify doesn't work quite right at this time:
-    # petrify can change a ref to a stratum to point at the system
-    # branch, but does it without adding an unpetrify-ref, and so
-    # unpetrify doesn't undo the change. We ignore this bug for the
-    # time being, in order to make the test suite pass. When the
-    # petrification code has been cleaned up to not be so hairy,
-    # we'll fix the test and the code.
-    #
-    # We would like to verify the result like this:
-    #
-    #   list_refs $(find . -type f) > "$DATADIR/refs.now"
-    #   diff -u "$DATADIR/refs.remembered" "$DATADIR/refs.now"
-    #
-    # However, due to the bug, we have to do it in a more complicated
-    # manner.
-
-    list_refs $(find . -type f) |
-    while read filename ref
-    do
-        orig=$(awk -v "f=$filename" '$1 == f { print $2 }' \
-            "$DATADIR/refs.remembered")
-        if [ "$orig" != "$ref" ] && [ "$ref" != "$MATCH_1" ]
-        then
-            die "Un-petrified ref: $filename $ref (should be $orig)"
-        fi
-    done
-
-    IMPLEMENTS WHEN petrifying (\S+)
-    cd "$DATADIR/workspace/$MATCH_1/test/morphs"
-    run_morph petrify
-
-    IMPLEMENTS WHEN unpetrifying (\S+)
-    cd "$DATADIR/workspace/$MATCH_1/test/morphs"
-    run_morph unpetrify
-
-    IMPLEMENTS THEN (\S+) is petrified
-    cd "$DATADIR/workspace/$MATCH_1/test/morphs"
-    assert_morphologies_are_petrified "$MATCH_1" $(find . -type f)
-
 Generating a manifest.
 
     IMPLEMENTS GIVEN a system artifact