diff --git a/src/python/jw/pkg/lib/pm/dpkg.py b/src/python/jw/pkg/lib/pm/dpkg.py
index b2ad671e..9255976f 100644
--- a/src/python/jw/pkg/lib/pm/dpkg.py
+++ b/src/python/jw/pkg/lib/pm/dpkg.py
@@ -94,6 +94,111 @@ async def list_files(
     file_list_str = await run_dpkg(['-L', *names], sudo = False, ec = ec)
     return file_list_str.splitlines()
 
+async def _file_name_version(
+    path: str,
+    ec: ExecContext | None = None,
+) -> tuple[str, str]:
+    """Return the (name, version) pair of a local deb file."""
+    out = await run_dpkg(['-I', path], sudo = False, throw = True, ec = ec)
+    name: str | None = None
+    version: str | None = None
+    for line in out.splitlines():
+        line = line.strip()
+        if line.startswith('Package: '):
+            name = line[len('Package: '):].strip()
+        elif line.startswith('Version: '):
+            version = line[len('Version: '):].strip()
+    if name is None or version is None:
+        raise Exception(f'cannot read the package name and version of {path}')
+    return name, version
+
+async def _simulate_install(
+    files: list[str],
+    expected: set[str],
+    ec: ExecContext | None = None,
+) -> None:
+    """Gate a direct dpkg install on an apt simulation.
+
+    dpkg -i leaves a half-configured package when a dependency is
+    missing, instead of aborting the transaction cleanly, so the
+    install is simulated first and refused when the simulation
+    would install or remove anything but the expected packages.
+    """
+    result = await run_sudo(
+        ['/usr/bin/apt-get', '-s', '--no-install-recommends', 'install', *files],
+        ec = ec,
+        cmd_input = InputMode.NonInteractive,
+        throw = False,
+    )
+    out = result.stdout_str
+    if result.status != 0:
+        raise Exception(f'apt simulation of the direct install failed:\n{out}')
+    inst: list[str] = []
+    remv: list[str] = []
+    for line in out.splitlines():
+        parts = line.split()
+        if parts and parts[0] == 'Inst':
+            inst.append(parts[1])
+        elif parts and parts[0] == 'Remv':
+            remv.append(parts[1])
+    pulled = [pkg for pkg in inst if pkg not in expected]
+    if pulled or remv:
+        raise Exception(f'apt simulation would install {pulled} or remove {remv}')
+
+async def install_packages(
+    paths: Iterable[str],
+    ec: ExecContext | None = None,
+    force: bool = False,
+    only_update: bool = False,
+) -> None:
+    """Install local deb files.
+
+    Every install is gated on an apt simulation, which refuses the
+    transaction when it would install or remove anything but the
+    given files' own packages; see _simulate_install().
+
+    Files are classified against the installed state of their
+    packages: files for packages that are not installed are
+    installed fresh, files with another version installed are
+    upgraded, and files whose version is already installed are
+    reinstalled with -i --force-reinstall when force is set and
+    skipped otherwise. The upgrades run before the reinstalls.
+
+    With only_update, a file for a package that is not installed
+    raises before anything is installed.
+    """
+    paths = list(paths)
+    if not paths:
+        return
+    update: list[str] = []
+    reinstall: list[str] = []
+    not_installed: list[str] = []
+    names: dict[str, str] = {}
+    for path in paths:
+        name, version = await _file_name_version(path, ec = ec)
+        names[path] = name
+        pkgs = list(await query_packages([name], ec = ec, throw = False))
+        if not pkgs:
+            (not_installed if only_update else update).append(path)
+            continue
+        if version in {p.version for p in pkgs if p.version}:
+            reinstall.append(path)
+            continue
+        update.append(path)
+    if not_installed:
+        raise Exception(
+            'only_update: package not installed for ' +
+            '\n'.join(f'  {p}' for p in not_installed)
+        )
+    selected = [*update, *reinstall] if force else update
+    if not selected:
+        return
+    await _simulate_install(selected, {names[path] for path in selected}, ec = ec)
+    if update:
+        await run_dpkg(['-i', *update], sudo = True, ec = ec)
+    if force and reinstall:
+        await run_dpkg(['-i', '--force-reinstall', *reinstall], sudo = True, ec = ec)
+
 def _parse_verify_output(
     pkg: str,
     output: str,
diff --git a/src/python/jw/pkg/lib/pm/rpm.py b/src/python/jw/pkg/lib/pm/rpm.py
index cb63e26a..29070878 100644
--- a/src/python/jw/pkg/lib/pm/rpm.py
+++ b/src/python/jw/pkg/lib/pm/rpm.py
@@ -80,6 +80,69 @@ async def list_files(
     )
     return stdout.splitlines()
 
+async def _file_name_version(
+    path: str,
+    ec: ExecContext | None = None,
+) -> tuple[str, str]:
+    """Return the (name, version-release) pair of a local rpm file."""
+    out = await run_rpm(
+        ['-qp', '--queryformat', '%{NAME}\t%{VERSION}-%{RELEASE}', path],
+        throw = True,
+        sudo = False,
+        mode = InputMode.NonInteractive,
+        ec = ec
+    )
+    name, version = out.split('\t', 1)
+    return name, version
+
+async def install_packages(
+    paths: Iterable[str],
+    ec: ExecContext | None = None,
+    force: bool = False,
+    only_update: bool = False,
+) -> None:
+    """Install local rpm files.
+
+    Files are classified against the installed state of their
+    packages: files for packages that are not installed are
+    installed fresh, files with another version installed are
+    upgraded, and files whose version is already installed are
+    reinstalled with -U --reinstall when force is set and
+    skipped otherwise, because plain -U refuses a package that
+    is already installed. The upgrades run before the
+    reinstalls: --reinstall aborts the whole transaction when a
+    file of the incoming package differs from the installed
+    one, which is exactly what an upgrade changes.
+
+    With only_update, a file for a package that is not installed
+    raises before anything is installed.
+    """
+    paths = list(paths)
+    if not paths:
+        return
+    update: list[str] = []
+    reinstall: list[str] = []
+    not_installed: list[str] = []
+    for path in paths:
+        name, version = await _file_name_version(path, ec = ec)
+        pkgs = list(await query_packages([name], ec = ec, throw = False))
+        if not pkgs:
+            (not_installed if only_update else update).append(path)
+            continue
+        if version in {p.version for p in pkgs if p.version}:
+            reinstall.append(path)
+            continue
+        update.append(path)
+    if not_installed:
+        raise Exception(
+            'only_update: package not installed for ' +
+            '\n'.join(f'  {p}' for p in not_installed)
+        )
+    if update:
+        await run_rpm(['-U', *update], sudo = True, ec = ec)
+    if force and reinstall:
+        await run_rpm(['-U', '--reinstall', *reinstall], sudo = True, ec = ec)
+
 def _parse_verify_output(
     pkg: str,
     output: str,
diff --git a/test/unit/python/jw/pkg/lib/pm/dpkg/test.py b/test/unit/python/jw/pkg/lib/pm/dpkg/test.py
index 66f06df6..bb8a9dba 100644
--- a/test/unit/python/jw/pkg/lib/pm/dpkg/test.py
+++ b/test/unit/python/jw/pkg/lib/pm/dpkg/test.py
@@ -5,7 +5,7 @@ import asyncio
 from typing import override
 
 from jw.pkg.lib.ec.Local import Local
-from jw.pkg.lib.pm.dpkg import list_files
+from jw.pkg.lib.pm.dpkg import install_packages, list_files
 from jw.pkg.lib.Result import Result
 
 class CannedLocal(Local):
@@ -79,3 +79,261 @@ assert cl2.cmds == [
 cl3 = CannedTwoStage('', '')
 assert asyncio.run(list_files([], ec = cl3)) == []
 assert cl3.cmds == []
+
+# -- install_packages --
+
+class InstallLocal(Local):
+    """A canned execution context that answers dpkg queries and
+    the apt simulation"""
+
+    def __init__(
+        self,
+        files: dict[str, str],
+        installed: dict[str, str],
+        simulate: str,
+        simulate_status: int = 0,
+    ) -> None:
+        super().__init__('local')
+        self.files = files
+        self.installed = installed
+        self.simulate = simulate
+        self.simulate_status = simulate_status
+        self.cmds: list[list[str]] = []
+
+    @override
+    async def _run(
+        self,
+        cmd: list[str],
+        wd: str | None,
+        verbose: bool,
+        cmd_input: bytes | None,
+        mod_env: dict[str, str] | None,
+        interactive: bool,
+        log_prefix: str,
+    ) -> Result:
+        self.cmds.append(cmd)
+        if '-I' in cmd:
+            return Result(stdout = self.files.get(cmd[-1], '').encode(), status = 0)
+        if cmd[0].endswith('dpkg-query'):
+            name = cmd[-1]
+            return Result(
+                stdout = self.installed.get(name, '').encode(),
+                status = 0 if name in self.installed else 1,
+            )
+        if '/usr/bin/apt-get' in cmd:
+            return Result(
+                stdout = self.simulate.encode(), status = self.simulate_status
+            )
+        return Result(stdout = b'', status = 0)
+
+def dpkg_args(cmd: list[str]) -> list[str]:
+    """The dpkg command without the sudo prefix and its options"""
+    return cmd[cmd.index('/usr/bin/dpkg'):]
+
+# -- Without force or only_update, all files go through a single
+# plain -i, gated on the apt simulation
+il = InstallLocal(
+    files = {'/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-41'},
+    simulate = 'Inst jw-base [1.0.0-42]\n',
+)
+asyncio.run(install_packages(['/a/jw-base-run-1.0.0-42.deb'], ec = il))
+sim = [cmd for cmd in il.cmds if '/usr/bin/apt-get' in cmd]
+assert len(sim) == 1
+args = sim[0][sim[0].index('/usr/bin/apt-get'):]
+assert '-s' in args
+assert '--no-install-recommends' in args
+assert args[-1] == '/a/jw-base-run-1.0.0-42.deb'
+installs = [dpkg_args(cmd) for cmd in il.cmds if '-i' in cmd]
+assert installs == [['/usr/bin/dpkg', '-i', '/a/jw-base-run-1.0.0-42.deb']]
+
+# -- Without force, a file whose version is already installed is
+# skipped
+il = InstallLocal(
+    files = {'/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-42'},
+    simulate = '',
+)
+asyncio.run(install_packages(['/a/jw-base-run-1.0.0-42.deb'], ec = il))
+assert not [cmd for cmd in il.cmds if '-i' in cmd]
+assert not [cmd for cmd in il.cmds if '/usr/bin/apt-get' in cmd]
+
+# -- An empty selection runs no commands
+il = InstallLocal(files = {}, installed = {}, simulate = '')
+assert asyncio.run(install_packages([], ec = il)) is None
+assert il.cmds == []
+
+# -- force reinstalls a file whose version is already installed
+il = InstallLocal(
+    files = {'/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-42'},
+    simulate = '',
+)
+asyncio.run(install_packages(['/a/jw-base-run-1.0.0-42.deb'], ec = il, force = True))
+assert dpkg_args(il.cmds[-1]) == [
+    '/usr/bin/dpkg',
+    '-i',
+    '--force-reinstall',
+    '/a/jw-base-run-1.0.0-42.deb',
+]
+
+# -- force upgrades a file whose package is installed in another
+# version with plain -i
+il = InstallLocal(
+    files = {'/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-41'},
+    simulate = 'Inst jw-base [1.0.0-42]\n',
+)
+asyncio.run(install_packages(['/a/jw-base-run-1.0.0-42.deb'], ec = il, force = True))
+assert dpkg_args(il.cmds[-1]) == ['/usr/bin/dpkg', '-i', '/a/jw-base-run-1.0.0-42.deb']
+
+# -- force installs a file whose package is not installed with
+# plain -i
+il = InstallLocal(
+    files = {'/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42'},
+    installed = {},
+    simulate = 'Inst jw-base [1.0.0-42]\n',
+)
+asyncio.run(install_packages(['/a/jw-base-run-1.0.0-42.deb'], ec = il, force = True))
+assert dpkg_args(il.cmds[-1]) == ['/usr/bin/dpkg', '-i', '/a/jw-base-run-1.0.0-42.deb']
+
+# -- A file that cannot be queried raises before the simulation
+# or the install
+il = InstallLocal(
+    files = {},
+    installed = {},
+    simulate = '',
+)
+try:
+    asyncio.run(install_packages(['/a/broken.deb'], ec = il, force = True))
+except Exception as e:
+    assert 'package name and version' in str(e)
+else:
+    raise AssertionError('expected an exception')
+assert not [cmd for cmd in il.cmds if '-i' in cmd]
+assert not [cmd for cmd in il.cmds if '/usr/bin/apt-get' in cmd]
+
+# -- only_update raises on files whose package is not installed,
+# before simulating or installing anything
+il = InstallLocal(
+    files = {
+        '/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42',
+        '/a/jw-foo-run-1.0.0-42.deb': 'Package: jw-foo\nVersion: 1.0.0-42',
+    },
+    installed = {'jw-base': 'jw-base|||||1.0.0-42'},
+    simulate = '',
+)
+try:
+    asyncio.run(
+        install_packages(
+            ['/a/jw-base-run-1.0.0-42.deb', '/a/jw-foo-run-1.0.0-42.deb'],
+            ec = il,
+            force = True,
+            only_update = True,
+        )
+    )
+except Exception as e:
+    assert 'only_update' in str(e)
+    assert '/a/jw-foo-run-1.0.0-42.deb' in str(e)
+else:
+    raise AssertionError('expected an exception')
+assert not [cmd for cmd in il.cmds if '-i' in cmd]
+assert not [cmd for cmd in il.cmds if '/usr/bin/apt-get' in cmd]
+
+# -- only_update installs an update of an installed package
+il = InstallLocal(
+    files = {'/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-41'},
+    simulate = 'Inst jw-base [1.0.0-42]\n',
+)
+asyncio.run(
+    install_packages(
+        ['/a/jw-base-run-1.0.0-42.deb'], ec = il, force = True, only_update = True
+    )
+)
+assert dpkg_args(il.cmds[-1]) == ['/usr/bin/dpkg', '-i', '/a/jw-base-run-1.0.0-42.deb']
+
+# -- force runs two installs for a mixed selection, the upgrades
+# first
+il = InstallLocal(
+    files = {
+        '/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42',
+        '/a/jw-base-run-1.0.0-41.deb': 'Package: jw-base\nVersion: 1.0.0-41',
+    },
+    installed = {'jw-base': 'jw-base|||||1.0.0-42'},
+    simulate = 'Inst jw-base [1.0.0-41]\n',
+)
+asyncio.run(
+    install_packages(
+        ['/a/jw-base-run-1.0.0-42.deb', '/a/jw-base-run-1.0.0-41.deb'],
+        ec = il,
+        force = True,
+    )
+)
+installs = [dpkg_args(cmd) for cmd in il.cmds if '-i' in cmd]
+assert installs == [
+    ['/usr/bin/dpkg', '-i', '/a/jw-base-run-1.0.0-41.deb'],
+    [
+        '/usr/bin/dpkg',
+        '-i',
+        '--force-reinstall',
+        '/a/jw-base-run-1.0.0-42.deb',
+    ],
+]
+
+# -- The simulation refuses the install when it would pull a
+# dependency
+il = InstallLocal(
+    files = {'/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42'},
+    installed = {},
+    simulate = 'Inst jw-base [1.0.0-42]\nInst jw-foo [2.0]\n',
+)
+try:
+    asyncio.run(
+        install_packages(['/a/jw-base-run-1.0.0-42.deb'], ec = il, force = True)
+    )
+except Exception as e:
+    assert 'would install' in str(e)
+    assert 'jw-foo' in str(e)
+else:
+    raise AssertionError('expected an exception')
+assert not [cmd for cmd in il.cmds if '-i' in cmd]
+
+# -- The simulation refuses the install when it would remove a
+# package
+il = InstallLocal(
+    files = {'/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42'},
+    installed = {},
+    simulate = 'Inst jw-base [1.0.0-42]\nRemv jw-old [1.0]\n',
+)
+try:
+    asyncio.run(
+        install_packages(['/a/jw-base-run-1.0.0-42.deb'], ec = il, force = True)
+    )
+except Exception as e:
+    assert 'remove' in str(e)
+    assert 'jw-old' in str(e)
+else:
+    raise AssertionError('expected an exception')
+assert not [cmd for cmd in il.cmds if '-i' in cmd]
+
+# -- A failed simulation, for instance unmet dependencies, aborts
+# with its output
+il = InstallLocal(
+    files = {'/a/jw-base-run-1.0.0-42.deb': 'Package: jw-base\nVersion: 1.0.0-42'},
+    installed = {},
+    simulate = (
+        'The following packages have unmet dependencies:\n'
+        ' jw-base : Depends: jw-foo but it is not going to be installed\n'
+    ),
+    simulate_status = 100,
+)
+try:
+    asyncio.run(
+        install_packages(['/a/jw-base-run-1.0.0-42.deb'], ec = il, force = True)
+    )
+except Exception as e:
+    assert 'unmet dependencies' in str(e)
+else:
+    raise AssertionError('expected an exception')
+assert not [cmd for cmd in il.cmds if '-i' in cmd]
diff --git a/test/unit/python/jw/pkg/lib/pm/rpm/test.py b/test/unit/python/jw/pkg/lib/pm/rpm/test.py
index e42ace0a..deed1875 100644
--- a/test/unit/python/jw/pkg/lib/pm/rpm/test.py
+++ b/test/unit/python/jw/pkg/lib/pm/rpm/test.py
@@ -6,7 +6,7 @@ from typing import override
 
 from jw.pkg.lib.ec.Local import Local
 from jw.pkg.lib.FlaggedFile import FlaggedFile
-from jw.pkg.lib.pm.rpm import _parse_verify_output, list_files
+from jw.pkg.lib.pm.rpm import _parse_verify_output, install_packages, list_files
 from jw.pkg.lib.Result import Result
 
 # -- _parse_verify_output --
@@ -101,3 +101,234 @@ assert cl.cmds[-1] == ['/usr/bin/rpm', '-qal']
 cl = CannedLocal('')
 assert asyncio.run(list_files([], ec = cl)) == []
 assert cl.cmds == []
+
+# -- install_packages --
+
+def rpm_args(cmd: list[str]) -> list[str]:
+    """The rpm command without the sudo prefix and its options"""
+    return cmd[cmd.index('/usr/bin/rpm'):]
+
+class DispatchLocal(Local):
+    """A canned execution context that answers rpm queries"""
+
+    def __init__(self, files: dict[str, str], installed: dict[str, str]) -> None:
+        super().__init__('local')
+        self.files = files
+        self.installed = installed
+        self.cmds: list[list[str]] = []
+
+    @override
+    async def _run(
+        self,
+        cmd: list[str],
+        wd: str | None,
+        verbose: bool,
+        cmd_input: bytes | None,
+        mod_env: dict[str, str] | None,
+        interactive: bool,
+        log_prefix: str,
+    ) -> Result:
+        self.cmds.append(cmd)
+        if '-qp' in cmd:
+            return Result(stdout = self.files.get(cmd[-1], '').encode(), status = 0)
+        if '-q' in cmd:
+            name = cmd[-1]
+            return Result(
+                stdout = self.installed.get(name, '').encode(),
+                status = 0 if name in self.installed else 1,
+            )
+        return Result(stdout = b'', status = 0)
+
+# -- Without force, a file whose version is already installed is
+# skipped, because plain -U refuses it
+dl = DispatchLocal(
+    files = {'/a/jw-base-run-1.0.0-42.x86_64.rpm': 'jw-base\t1.0.0-42'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-42\n'},
+)
+asyncio.run(install_packages(['/a/jw-base-run-1.0.0-42.x86_64.rpm'], ec = dl))
+assert not [cmd for cmd in dl.cmds if '-U' in cmd]
+
+# -- Without force, fresh and update files go through a single
+# plain -U
+dl = DispatchLocal(
+    files = {
+        '/a/jw-base-run-1.0.0-42.x86_64.rpm': 'jw-base\t1.0.0-42',
+        '/b/jw-foo-run-1.0.0-42.x86_64.rpm': 'jw-foo\t1.0.0-42',
+    },
+    installed = {'jw-base': 'jw-base|||||1.0.0-41\n'},
+)
+asyncio.run(
+    install_packages(
+        ['/a/jw-base-run-1.0.0-42.x86_64.rpm', '/b/jw-foo-run-1.0.0-42.x86_64.rpm'],
+        ec = dl,
+    )
+)
+installs = [cmd for cmd in dl.cmds if '-U' in cmd]
+assert len(installs) == 1
+assert installs[0][0] == '/usr/bin/sudo'
+assert rpm_args(installs[0]) == [
+    '/usr/bin/rpm',
+    '-U',
+    '/a/jw-base-run-1.0.0-42.x86_64.rpm',
+    '/b/jw-foo-run-1.0.0-42.x86_64.rpm',
+]
+
+# -- An empty selection installs nothing and runs no command
+dl = DispatchLocal(files = {}, installed = {})
+asyncio.run(install_packages([], ec = dl))
+assert dl.cmds == []
+
+# -- With force, a file whose version is already installed is reinstalled
+dl = DispatchLocal(
+    files = {'/a/jw-base-run-1.0.0-42.x86_64.rpm': 'jw-base\t1.0.0-42'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-42\n'},
+)
+asyncio.run(
+    install_packages(['/a/jw-base-run-1.0.0-42.x86_64.rpm'], ec = dl, force = True)
+)
+assert rpm_args(dl.cmds[-1]) == [
+    '/usr/bin/rpm',
+    '-U',
+    '--reinstall',
+    '/a/jw-base-run-1.0.0-42.x86_64.rpm',
+]
+
+# -- With force, a file with another version installed is a plain upgrade
+dl = DispatchLocal(
+    files = {'/a/jw-base-run-1.0.0-42.x86_64.rpm': 'jw-base\t1.0.0-42'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-41\n'},
+)
+asyncio.run(
+    install_packages(['/a/jw-base-run-1.0.0-42.x86_64.rpm'], ec = dl, force = True)
+)
+assert rpm_args(dl.cmds[-1]) == [
+    '/usr/bin/rpm',
+    '-U',
+    '/a/jw-base-run-1.0.0-42.x86_64.rpm',
+]
+
+# -- With force, a file for a package that is not installed is a plain
+# install
+dl = DispatchLocal(
+    files = {'/a/jw-base-run-1.0.0-42.x86_64.rpm': 'jw-base\t1.0.0-42'},
+    installed = {},
+)
+asyncio.run(
+    install_packages(['/a/jw-base-run-1.0.0-42.x86_64.rpm'], ec = dl, force = True)
+)
+assert rpm_args(dl.cmds[-1]) == [
+    '/usr/bin/rpm',
+    '-U',
+    '/a/jw-base-run-1.0.0-42.x86_64.rpm',
+]
+
+# -- An unqueryable file raises before anything is installed
+dl = DispatchLocal(files = {}, installed = {})
+try:
+    asyncio.run(
+        install_packages(['/a/jw-base-run-1.0.0-42.x86_64.rpm'], ec = dl, force = True)
+    )
+except Exception:
+    pass
+else:
+    raise AssertionError('expected an exception')
+assert not [cmd for cmd in dl.cmds if '-U' in cmd]
+
+# -- With force, a mixed transaction runs two installs, the upgrades first
+dl = DispatchLocal(
+    files = {
+        '/a/jw-base-run-1.0.0-42.x86_64.rpm': 'jw-base\t1.0.0-42',
+        '/a/jw-base-run-1.0.0-41.x86_64.rpm': 'jw-base\t1.0.0-41',
+    },
+    installed = {'jw-base': 'jw-base|||||1.0.0-42\n'},
+)
+asyncio.run(
+    install_packages(
+        ['/a/jw-base-run-1.0.0-42.x86_64.rpm', '/a/jw-base-run-1.0.0-41.x86_64.rpm'],
+        ec = dl,
+        force = True,
+    )
+)
+installs = [rpm_args(cmd) for cmd in dl.cmds if '-U' in cmd]
+assert installs == [
+    ['/usr/bin/rpm', '-U', '/a/jw-base-run-1.0.0-41.x86_64.rpm'],
+    [
+        '/usr/bin/rpm',
+        '-U',
+        '--reinstall',
+        '/a/jw-base-run-1.0.0-42.x86_64.rpm',
+    ],
+]
+
+# -- With only_update, a file whose package is not installed raises
+# before anything is installed
+dl = DispatchLocal(
+    files = {
+        '/a/jw-base-run-1.0.0-42.x86_64.rpm': 'jw-base\t1.0.0-42',
+        '/a/jw-foo-run-1.0.0-42.x86_64.rpm': 'jw-foo\t1.0.0-42',
+    },
+    installed = {'jw-base': 'jw-base|||||1.0.0-42\n'},
+)
+try:
+    asyncio.run(
+        install_packages(
+            ['/a/jw-base-run-1.0.0-42.x86_64.rpm', '/a/jw-foo-run-1.0.0-42.x86_64.rpm'],
+            ec = dl,
+            force = True,
+            only_update = True,
+        )
+    )
+except Exception as e:
+    assert 'only_update' in str(e)
+    assert '/a/jw-foo-run-1.0.0-42.x86_64.rpm' in str(e)
+else:
+    raise AssertionError('expected an exception')
+assert not [cmd for cmd in dl.cmds if '-U' in cmd]
+
+# -- With only_update, an update of an installed package is installed
+dl = DispatchLocal(
+    files = {'/a/jw-base-run-1.0.0-43.x86_64.rpm': 'jw-base\t1.0.0-43'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-42\n'},
+)
+asyncio.run(
+    install_packages(
+        ['/a/jw-base-run-1.0.0-43.x86_64.rpm'],
+        ec = dl,
+        force = True,
+        only_update = True,
+    )
+)
+installs = [rpm_args(cmd) for cmd in dl.cmds if '-U' in cmd]
+assert installs == [
+    ['/usr/bin/rpm', '-U', '/a/jw-base-run-1.0.0-43.x86_64.rpm'],
+]
+
+# -- With only_update and force off, a file whose version is
+# already installed is skipped
+dl = DispatchLocal(
+    files = {'/a/jw-base-run-1.0.0-42.x86_64.rpm': 'jw-base\t1.0.0-42'},
+    installed = {'jw-base': 'jw-base|||||1.0.0-42\n'},
+)
+asyncio.run(
+    install_packages(
+        ['/a/jw-base-run-1.0.0-42.x86_64.rpm'], ec = dl, only_update = True
+    )
+)
+assert not [cmd for cmd in dl.cmds if '-U' in cmd]
+
+# -- With only_update, all files absent raises without installing
+dl = DispatchLocal(
+    files = {'/a/jw-foo-run-1.0.0-42.x86_64.rpm': 'jw-foo\t1.0.0-42'},
+    installed = {},
+)
+try:
+    asyncio.run(
+        install_packages(
+            ['/a/jw-foo-run-1.0.0-42.x86_64.rpm'], ec = dl, only_update = True
+        )
+    )
+except Exception as e:
+    assert 'only_update' in str(e)
+else:
+    raise AssertionError('expected an exception')
+assert not [cmd for cmd in dl.cmds if '-U' in cmd]