The package fails to build on some archs. See
https://buildd.debian.org/status/package.php?p=btas&suite=sid

Able to reproduce the issue while building the package on pp64el and
checked the  build logs from pp64el
(https://buildd.debian.org/status/fetch.php?pkg=btas&arch=ppc64el&ver=1.0.0-1.1&stamp=1757416358&raw=0).
 From the logs,the issue seems to be because some test cases are falling
back to SVD. Maybe that is causing a slighthly more value than the
threshold.

Trying to check more on this.


2: ./unittest/ztensor_cp_test.cc:150: FAILED:
2:   CHECK(std::abs(diff) <= epsilon )
2: with expansion:
2:   0.0000118685 <= 0.00001
2:
2: Fast pseudo-inverse failed reverting to normal pseudo-inverse
2: Fast pseudo-inverse failed reverting to normal pseudo-inverse

Hello,
I found that the test case failure is not due to incorrect behavior but
rather seems like it is because of platform-specific floating-point
precision differences on ppc64le. The numerical error is marginal and
well within acceptable limits for floating-point operations involving
matrix decompositions and pseudo-inverses.

This appears to be a case where the test's absolute epsilon (|1e-5|) is
a bit strict for some platforms, especially when fallback to the normal
pseudo-inverse occurs (as the fast pseudo-inverse fails). The same issue
also appears to be for arm64.

To resolve this, I suggest for relaxing the epsilon slightly. Following
is the diff for that.

diff --git a/unittest/ztensor_cp_test.cc b/unittest/ztensor_cp_test.cc
index e9f9a0f..4cd8446 100644
--- a/unittest/ztensor_cp_test.cc
+++ b/unittest/ztensor_cp_test.cc
@@ -26,6 +26,9 @@ TEST_CASE("ZCP") {
    // double epsilon = fmax(1e-10, std::numeric_limits<double>::epsilon());
    double epsilon = 1e-5;

+  #if defined(__PPC64__) || defined(__powerpc64__)
+    epsilon = 2e-5;
+  #endif
    ztensor Z3(3, 2, 4);
std::ifstream inp3(__dirname + "/z-mat3D.txt");
    if (inp3.is_open()) {
debian@ltc-zz14-lp9:~/test-btas/btas-1.0.0/debian/patches$

Thanks and regards.

We believe that the bug you reported is fixed in the latest version of
btas, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1115288@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Michael Banck <mbanck@debian.org> (supplier of updated btas package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Sat, 22 Aug 2026 14:22:04 +0200
Source: btas
Architecture: source
Version: 1.0.0-2
Distribution: unstable
Urgency: medium
Maintainer: Debichem Team <debichem-devel@lists.alioth.debian.org>
Changed-By: Michael Banck <mbanck@debian.org>
Closes: 1115288
Changes:
 btas (1.0.0-2) unstable; urgency=medium
 .
   * debian/patches/relax_test_epsilon.patch: New patch, relaxes test thresholds
     on non-amd64 architectures, thanks to Tanushree Shah (Closes: #1115288).
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