won't build from source

[Folkert van Heusden]

When I invoke

  dpkg-buildpackage -us -uc

on the package, I eventually get:

FAIL: testpkcs11.sh
===================

Testing PKCS11 support
usage: ../../tests/testpkcs11.sh: [pkcs15|softhsm|sc-hsm]
assuming 'softhsm'

* Initializing smart card... ok
* Token: pkcs11:model=SoftHSM%20v2;manufacturer=SoftHSM%20project;serial=e2da1c3b8462cf8b;token=GnuTLS-Test
* Setting SO PIN... ok
* Re-setting SO PIN... ok
* Setting too large SO PIN... ok
* Setting large SO PIN... ok
* Re-setting SO PIN... ok
* Setting user PIN... ok
* Re-setting user PIN... ok
* Setting too large user PIN... ok
* Setting large user PIN... ok
* Re-setting user PIN... ok
* Writing a client private key... ok
* Checking whether object was marked private... ok
* Checking whether object was marked sensitive... ok
* Generating ECC private key (256)... ok
* Deleting private key... ok
* Generating ECC private key without --login (256)... ok
* Deleting private key... ok
* Generating ECC private key (384)... ok
* Deleting private key... ok
* Generating RSA private key (2048)... ok
* Deleting private key... ok
* Generating DSA private key (3072)... ok
* Deleting private key... ok
* Importing RSA private key (1024)... ok
* Deleting private key... ok
* Importing ECC private key (256)... ok
* Deleting private key... ok
* Importing DSA private key (2048)... ok
* Deleting private key... ok
* Generating RSA private key (1024)... ok
* Checking whether generated private key was marked private... ok
* Checking whether private key was marked sensitive... ok
* Change the CKA_ID of generated private key... ok
* Exporting public key of generated private key... ok
* Change the CKA_LABEL of generated private key... ok
* Exporting public key as SO... ok
* List private key without GNUTLS_PIN... ok
* Generating client certificate... ok
* Writing client certificate... ok
* Checking whether ID was correctly set... ok
* Checking whether object was public... ok
* Writing certificate of client's CA... ok
* Testing certificate flags... ok
* Checking output of certificateok
* Trying to obtain back the cert... ok
* Trying to obtain the full chain... ok
* Writing the server private key... ok
* Writing the server certificate... ok
* Writing the server public key... ok
* Testing signatures using the private key... ok
* Testing RSA-PSS signatures using the private key... ok
* Testing signatures using the private key (with ID)... ok
* Using PKCS #11 with gnutls-cli (full URLs)... Failure: Connection (with files) should have succeeded!
FAIL testpkcs11.sh (exit status: 1)

============================================================================
Testsuite summary for GnuTLS 3.6.15
============================================================================
# TOTAL: 475
# PASS: 457
# SKIP: 17
# XFAIL: 0
# FAIL: 1
# XPASS: 0
# ERROR: 0

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: libgnutls30 3.7.1-3ubuntu1
ProcVersionSignature: Ubuntu 5.11.0-22.23-generic 5.11.21
Uname: Linux 5.11.0-22-generic x86_64
ApportVersion: 2.20.11-0ubuntu65.1
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Fri Jul 23 09:58:27 2021
InstallationDate: Installed on 2021-01-05 (198 days ago)
InstallationMedia: Ubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
SourcePackage: gnutls28
UpgradeStatus: Upgraded to hirsute on 2021-06-18 (35 days ago)