diff --git a/.gitignore b/.gitignore
index 6087923..bba3f77 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,12 @@
 /pyMapVBVD-0.5.3.tar.gz
 /pyMapVBVD-0.5.4.tar.gz
 /pyMapVBVD-0.5.4-test-data.tar.xz
+/pyMapVBVD-0.5.5.tar.gz
+/pyMapVBVD-0.5.5-test-data.tar.xz
+/pyMapVBVD-test-data.tar.xz
+/pyMapVBVD-0.5.6.tar.gz
+/pyMapVBVD-0.5.7.tar.gz
+/pyMapVBVD-test-data.tar.zst
+/pymapvbvd-0.6.0.tar.gz
+/pymapvbvd-test-data.tar.zst
+/pymapvbvd-0.6.1.tar.gz
diff --git a/get_test_data.sh b/get_test_data.sh
index ab40fbd..395006a 100755
--- a/get_test_data.sh
+++ b/get_test_data.sh
@@ -11,8 +11,13 @@ Usage: $1 VERSION
 
 Generate a source archive containing the test data files for pyMapVBVD that are
 tracked in git LFS and are not included in the default source archive. The
-result will be named pyMapVBVD-\${VERSION}-test-data.tar.xz and will be written
+result will be named pymapvbvd-test-data.tar.zst and will be written
 into the current working directory.
+
+The script attempts to produce a reproducible archive to avoid uploading
+near-duplicate archives to the lookaside cache when the test data does not
+change from one version to the next. Accordingly, the top-level directory
+pymapvbvd-\${VERSION}/ is omitted from the archived paths.
 EOF
 }
 
@@ -40,8 +45,8 @@ GITDIR="$(echo "${FORGEURL}" | sed -r 's@.*/@@')"
 
 #SOURCE0="${FORGEURL}/archive/${VERSION}/pdfminer.six-${VERSION}.tar.gz"
 #TARNAME="$(basename "${SOURCE0}")"
-TARDIR="pyMapVBVD-${VERSION}"
-NEWTAR="${TARDIR}-test-data.tar.xz"
+TARDIR="pymapvbvd-${VERSION}"
+NEWTAR='pymapvbvd-test-data.tar.zst'
 
 SAVEDIR="${PWD}"
 XDIR="$(mktemp -d)"
@@ -61,8 +66,20 @@ git lfs ls-files -n |
 		ln "${fn}" "${DESTDIR}/$(basename "${fn}")"
 	done
 
-cd "${XDIR}"
-tar -cv "${TARDIR}/" | xz -9e > "${NEWTAR}"
+cd "${XDIR}/${TARDIR}"
+# https://www.gnu.org/software/tar/manual/html_section/Reproducibility.html
+# We discard mtimes entirely, since git doesn’t store mtimes and they are just
+# the time we did the git clone.
+TZ=UTC LC_ALL=C tar \
+		--create --verbose \
+		--sort=name \
+		--format=posix \
+		--numeric-owner --owner=0 --group=0 \
+		--mode=go+u,go-w \
+		--pax-option='delete=atime,delete=ctime' \
+		--clamp-mtime --mtime='@0' \
+		. |
+	zstdmt --ultra -22 > "${XDIR}/${NEWTAR}"
 
 cd "${SAVEDIR}"
 mv -v "${XDIR}/${NEWTAR}" .
diff --git a/python-pymapvbvd.rpmlintrc b/python-pymapvbvd.rpmlintrc
new file mode 100644
index 0000000..bab460e
--- /dev/null
+++ b/python-pymapvbvd.rpmlintrc
@@ -0,0 +1,9 @@
+# Not real spelling errors.
+# - "dat" is from the extension ".dat"
+# - "twix" is a data format
+addFilter(r" spelling-error \('(dat|twix)',")
+# This source cannot be a URL because we must use a script to download its
+# contents from git-lfs.
+addFilter(r" invalid-url Source[0-9]+: pymapvbvd-test-data\.tar\.zst$")
+# Bogus; it is a perfectly fine zstandard file.
+addFilter(r" inconsistent-file-extension pymapvbvd-test-data\.tar\.zst$")
diff --git a/python-pymapvbvd.spec b/python-pymapvbvd.spec
index aba8ec0..fbb7b36 100644
--- a/python-pymapvbvd.spec
+++ b/python-pymapvbvd.spec
@@ -1,40 +1,27 @@
-# In the releases mentioned in the expression, the system versioneer is too old
-# for the generated _version.py to have the get_version() function, and too old
-# for the License tag to be accurate. We must use the bundled, amalgamated
-# versioneer.py to generate _version.py.
-#
-# Otherwise, we can use the system versioneer to generate _version.py, and can
-# remove the bundled, amaglamated versioneer.py to indicate we aren’t using it.
-%bcond bundled_versioneer %{expr:0%{?fc37} || 0%{?fc38} || 0%{?el9}}
-
 Name:           python-pymapvbvd
-Version:        0.5.4
+Version:        0.6.1
 Release:        %autorelease
 Summary:        Python twix file reader
 
 # The entire source is MIT, except:
-#   - The script versioneer.py and the file pymapvbvd/_version.py, which was
-#     generated by it, are both Unlicense.
+#   - The file pymapvbvd/_version.py, which is generated by python-versioneer,
+#     shares its license (Unlicense, for recent versions of Versioneer); see
+#     also versioneer.py (which is removed in %%prep)
 License:        MIT AND Unlicense
 URL:            https://github.com/wtclarke/pymapvbvd
-Source0:        %{pypi_source pyMapVBVD}
+Source0:        %{pypi_source pymapvbvd}
 # Generated with Source2: ./get_test_data.sh %%{version}
-Source1:        pyMapVBVD-%{version}-test-data.tar.xz
+Source1:        pymapvbvd-test-data.tar.zst
 Source2:        get_test_data.sh
 
-BuildArch:      noarch
-# The library assumes that the host and the file format are both little-endian.
-# The necessary patch would not be trivial. Queried upstream:
-#
-# Big-endian host support?
-# https://github.com/wtclarke/pymapvbvd/issues/35
-#
-# A bug will be filed blocking F-ExcludeArch-s390x, per
-# https://docs.fedoraproject.org/en-US/packaging-guidelines/#_architecture_build_failures,
-# once the package is imported.
-ExcludeArch:    s390x
+BuildSystem:            pyproject
+BuildOption(generate_buildrequires): -x tests
+BuildOption(install):   -l mapvbvd
 
-BuildRequires:  python3-devel
+BuildArch:      noarch
+# PyMapVBVD assumes the platform is little-endian
+# https://bugzilla.redhat.com/show_bug.cgi?id=2225518
+ExcludeArch:    s390x
 
 %global common_description %{expand:
 Python port of the Matlab mapVBVD tool for reading Siemens raw data 'twix'
@@ -52,50 +39,31 @@ Summary:        %{summary}
 
 # The generated _version.py has the same license as python3dist(versioneer),
 # but we do not consider it to be bundled from Versioneer.
-%if %{with bundled_versioneer}
-# While versioneer.py is a bundled copy of python3dist(versioneer) = 0.28, it
-# is not included in the binary RPMs, so we still do not treat it as bundled,
-# and there is no corresponding virtual Provides.
-%endif
 
 %description -n python3-pymapvbvd %{common_description}
 
 
 %prep
-%autosetup -n pyMapVBVD-%{version} -p1
-%setup -q -T -D -b 1 -n pyMapVBVD-%{version}
-%if %{without bundled_versioneer}
+%autosetup -n pymapvbvd-%{version} -p1
+%setup -q -T -D -a 1 -c -n pymapvbvd-%{version}
+# We can use the system versioneer to generate _version.py, and can remove the
+# bundled, amaglamated versioneer.py to indicate we aren’t using it.
 rm -v versioneer.py
-%endif
 
 
-%generate_buildrequires
+%generate_buildrequires -p
 export SETUPTOOLS_SCM_PRETEND_VERSION='%{version}'
-%if %{with bundled_versioneer}
-export PYTHONPATH="${PWD}"
-%endif
-%pyproject_buildrequires -x tests
 
 
-%build
+%build -p
 export SETUPTOOLS_SCM_PRETEND_VERSION='%{version}'
-%if %{with bundled_versioneer}
-export PYTHONPATH="${PWD}"
-%endif
-%pyproject_wheel
 
 
-%install
-%pyproject_install
-%pyproject_save_files mapvbvd
-
-
-%check
+%check -a
 %pytest -v
 
 
 %files -n python3-pymapvbvd -f %{pyproject_files}
-# pyproject_files handles LICENSE; verify with “rpm -qL -p …”
 %doc README.md
 
 
diff --git a/sources b/sources
index 87b5987..8624192 100644
--- a/sources
+++ b/sources
@@ -1,2 +1,2 @@
-SHA512 (pyMapVBVD-0.5.4.tar.gz) = 1512db1aa15dcac460b87f100ecd9539a274f6b740f4024aee283cbc7fe3a0f466accd01e76bc393492c0088a797adaa0ae158c58ee36310ff6b0bac1666fb30
-SHA512 (pyMapVBVD-0.5.4-test-data.tar.xz) = c29bcd449fb39d2449a1c3e555d4d61f80bc09102156d2103366bad610fe70e3c0152e417899db4e51879faec61a6d087576332c16f82bb30eedc2296026bef6
+SHA512 (pymapvbvd-0.6.1.tar.gz) = b1c12e8f4c261522858feea9c66b5c174b37203a73a54aac8e2bbfb3ab7b1933ba44c9c172aa9cf7a97dba0c4554d99042c042fef9b42f73e912f747ceac1d55
+SHA512 (pymapvbvd-test-data.tar.zst) = 638be0a8ad0e0876b13948d657bcf921e18938e964215c0c61b9deb6eb5f3abee449a0391238e8e60ffef55c4ca3b9c2906f4c4fd3655e23eed3567279e72323