Four EasyBuild 5 surfaces the earlier pages skipped

Four surfaces the earlier pages skipped. Each one is a new object, not a flag on an old one.

Four EasyBuild 5 surfaces the earlier pages skipped.

Four EasyBuild 5 surfaces. An install lock is not a Resolvo lock. A Dataset is a module whose payload is data.

Questions

• What does an EasyBuild install lock prevent, and how is it not a Resolvo lock?

• When does --bwrap move bytes, and when does the namespace fail?

• What does a Dataset easyconfig install that a software easyconfig does not?

What you will be able to do

1. Name the directory EasyBuild uses for install locks, and the flag that ignores them.

2. Say what EBPYTHONPREFIXES is for, and what a 5.3 entry point changes about a Python module.

3. Install a dataset as a module and depend on it from a software easyconfig, naming the two path variables that keep data off the software prefix.

Before this page

• eb-stack ports a recipe and bumps one: Resolvo locks. The locks on this page are files on disk during eb.

• Languages that bring their own package manager: Python extensions. EBPYTHONPREFIXES is how a second prefix is visible.

• The isolation policy: the build’s environment. --bwrap is a later isolation.

Four EasyBuild 5 surfaces extend the machinery of chapters 13 to 19. They are not part of eb-stack. They explain a campaign finding of class install or runtime, and can name the framework rather than the recipe.

Install locks are not solver locks

Two eb processes installing the same easyconfig into the same prefix corrupt the tree. EasyBuild writes a lock file for the duration of an installation. --locks-dir sets the directory. The default is a .locks subdirectory of the software installation prefix. Documentation says the lock directory should be on a shared filesystem. --ignore-locks is the escape that two operators will reach for. A site should not leave --ignore-locks on. That lock is a mutex. It names no versions. It solves no SAT instance. eb-stack ports a recipe and bumps one’s locks/default.lock.json as a Resolvo assignment. Mixing the words in a status report escalates a “lock wait” as a solver bug. --wait-on-lock-* controls whether a second process waits or errors. The filetools API is create_lock, check_lock, remove_lock. A stale lock after a killed eb is an operator problem on the shared filesystem, not a recipe problem.

–bwrap installs to a temporary namespace

--bwrap (EasyBuild 5.3, improved in 5.4.0 for read‑only filesystems and --subdir-{modules,software}) builds and installs within a bubblewrap namespace. --bwrap then transfers the result to the final prefix. --bwrap-installpath is the temporary location. The goal is a prefix that other users must not see while it is partially written. The goal includes a CernVM-FS or similar read‑only view that cannot be written in place. The overlayfs work in 5.4.0 enables EESSI‑style writable‑over‑read‑only installations to use that overlay. RPATH wrappers still fail when /tmp is mounted with noexec (#4910). That is independent of --bwrap. The wrapper scripts need an executable temporary directory. --tmpdir on an exec filesystem is the fix, not a bwrap flag. The isolation policy defines the build’s environment. --bwrap is the namespace isolation EasyBuild 5 ships. It needs user namespaces and a bwrap binary; without those the flag fails before any recipe runs.

EBPYTHONPREFIXES and entry points

EasyBuild allows a Python installation to see packages in another prefix via EBPYTHONPREFIXES. A user or site prefix on top of EESSI can contribute .so and .py files without rebuilding CPython. A module that only wraps a site wheel can become loadable. EasyBuild 5.3 added entry-point handling. A console script installed into an extension prefix appears on PATH when the extension’s module is loaded. A campaign verifies python -c 'import pkg'. A campaign that never runs the console script will not encounter a missing entry point. binary_verified in a campaign finding is a typed failure. A log must name the command the user will type.

Dataset is a module whose payload is data

Datasets are added as modules in EasyBuild 5.1.0. The origin is Sam Moors’ EUM’24 talk. The easyconfig uses data_sources instead of, or in addition to, sources.

easyblock = 'Dataset'

name = 'RFdiffusion-models'
version = '1.1.0'
toolchain = SYSTEM

source_urls = ['https://example.com/data/']
data_sources = ['example-data-%(version)s.tar.gz']
checksums = ['d3adb33f...']

The Dataset easyblock inherits from Binary. No compile step runs. The install_step extracts into the data prefix. The default value of extract_sources is true. The cleanup_data_sources deletes fetched archives after install. From 5.4.0, Dataset can store extracted files in a SHA256 content-addressed object store and reuse a readable existing object. Reuse is is_readable() on that hash path. It does not re-hash the stored object. A writable sibling under the object-storage root is trusted as if EasyBuild wrote it. The object_storage_ignore_dirs lists directories to keep out of that store. The . denotes the whole installdir. Two path variables keep data off the software prefix.

export EASYBUILD_SOURCEPATH_DATA=/sources/data
export EASYBUILD_INSTALLPATH_DATA=/data
eb RFdiffusion-models-1.1.0.eb
module load RFdiffusion-models/1.1.0

When installpath-data is unset, installpath combined with subdir-data (default data) is used. The module may appear in a software easyconfig’s dependencies list. A GROMACS that requires a weight file depends on the dataset module in the same way it depends on FFTW. The robot resolves the dependency. The payload consists of bytes, not a binary.

EB-Five-1 — Which lock, which prefix

Four incidents. Name the EasyBuild 5 surface, and the first check.

1. Two eb processes on a shared prefix, same easyconfig, one dies with a lock error, the other is still in install_step.

2. --bwrap on a node where /tmp is noexec; the log talks about RPATH wrappers.

3. A user prefix installed with EESSI-extend; import numpy works from the EESSI CPython; the f2py console script is not on PATH.

4. A two-gigabyte weight tarball landed under .../software/linux/x86_64/amd/zen3/software/ next to GROMACS.

Solution

1. Install locks. Check --locks-dir (default .locks under the software prefix) and whether the surviving process still has the mutex. Not a Resolvo lock. Do not pass --ignore-locks to “fix” it.

2. --bwrap plus #4910. Check the /tmp mount options. The wrapper binaries need exec.

3. Entry points / EBPYTHONPREFIXES. import finding the package does not put a console script on PATH. Verify the command the user types, in addition to the import.

4. A Dataset easyconfig was not used, or EASYBUILD_INSTALLPATH_DATA was unset and the default subdir-data was not what the site expected. Weights are data. They get a data prefix and a module, not a software prefix.

sourcesWhere this page comes from

EasyBuild docs, last update 2026-08-09:

• `--bwrap, --locks-dir, --ignore-locks <https://docs.easybuild.io/version-specific/eb-help/>`_

• Datasets (5.1.0, data_sources, EASYBUILD_SOURCEPATH_DATA, EASYBUILD_INSTALLPATH_DATA)

• Dataset easyblock (object_storage_ignore_dirs, no compile)

• EasyBuild 5.4.0 notes: --bwrap on overlayfs / read-only filesystems (#5173)

• EasyBuild #4910: RPATH wrappers and noexec /tmp

What to remember

• An install lock is a mutex on a shared prefix. A Resolvo lock is an assignment of versions. They share a word and nothing else.

• --bwrap installs in a namespace and then moves. /tmp noexec breaks the RPATH wrappers.

• EBPYTHONPREFIXES makes a second Python prefix visible. Entry points are a 5.3 addition; an import test does not cover them.

• A Dataset module is data. EASYBUILD_INSTALLPATH_DATA keeps it off the software prefix. Software depends on it like any other module.