• Read debian/copyright in full (DEP-5, correct Format: value) and every file of the tree: .gitignore, LICENSE, Makefile, Makefile.defs, README.md, go.mod, go.sum, main.go, main_test.go, secsipidx.1, .github/FUNDING.yml, .github/workflows/go.yml, .github/workflows/release.yaml, csecsipid/{Makefile,csecsipid.go,libsecsipid.h,secsipid-1.pc,secsipid.h}, secsipid/{.gitignore,cache.go,cache_redis.go,secsipid.go,secsipid_test.go,system_cas.go}. Licensing evidence was collected with a tree-wide grep for Copyright/(C)/©/SPDX-License-Identifier/Licensed under/Permission is hereby granted/GNU/Apache/MPL/public domain: notices exist only in LICENSE, README.md:341-347 and debian/copyright.
• LICENSE is the Clear BSD licence of asipto.com (2019-2020); the Files: * stanza reproduces that text under BSD-3-Clause-Clear, which is DFSG-free and in main elsewhere (e.g. /usr/share/doc/libsvtav1enc4/copyright, /usr/share/doc/libopenblas0/copyright, /usr/share/doc/firmware-ath9k-htc/copyright). No non-commercial, no-modification, field-of-use or other non-free wording exists in the tree; a permissive notice whose text must be reproduced is reproduced in full, so no /usr/share/common-licenses pointer is involved and none is wrong.
• secsipid/system_cas.go is the only file with foreign provenance: its header says /** Copied and pasted from go standard library: "crypto/x509" package!! **/. The overriding Files: secsipid/system_cas.go stanza names The Go Authors (2009) with BSD-3-Clause and gives that licence text in full, so the copied code is credited; the file's Clear BSD parts are compatible with it. No other copied or vendored code exists (the only imports are github.com/google/uuid, github.com/redis/go-redis/v9 and the test-only github.com/gomagedon/expectate; no vendor/ directory).
• csecsipid/libsecsipid.h is a build product, not a missing source: it begins /* Code generated by cmd/cgo; DO NOT EDIT. */, is generated from csecsipid/csecsipid.go, and the build regenerates it in _build/src/github.com/asipto/secsipidx/csecsipid (make lib calls go build -buildmode=c-shared; its output header is the file that install-dev copies). The preferred form for modification is therefore in the package and the installed copy is the regenerated one; not a licensing or DFSG issue.
• No other built or opaque files: no images, fonts, sounds, PDFs, archives or minified code; main_test.go and secsipid/secsipid_test.go embed no PEM certificates or keys, so there is no test data of unclear provenance.
• debian/copyright coverage: Files: * reaches every path (DEP-5 * matches /), and Files: secsipid/system_cas.go, Files: secsipidx.1 and Files: debian/* override it exactly where needed (later stanzas win). No Files-Excluded is needed: nothing was removed from the tree. The secsipidx.1 stanza correctly names its author Victor Seva, who wrote it.
• Packaging files all read: debian/control, rules, changelog, source/format (3.0 quilt), the three .install files, secsipidx.manpages, libsecsipid2.symbols, libsecsipid2.lintian-overrides, gbp.conf, salsa-ci.yml, upstream/metadata; the .debian.tar.xz contains exactly these and no debian/patches, and there are no maintainer scripts or *.maintscript files, so idempotence does not arise.
• Build dependencies resolve: golang-github-redis-go-redis-dev 9.17.2 (the v9 API used in secsipid/cache_redis.go: ParseURL, Options fields, Get/Set/TxPipelined, redis.Nil), golang-github-google-uuid-dev 1.6.0, golang-github-gomagedon-expectate-dev 1.3.1 (test-only, correctly <!nocheck> since only dh_auto_test needs it) and dpkg-dev 1.23.11 all exist in the archive.
• Built-Using: ${misc:Built-Using} is not an unset substvar: /usr/bin/dh_golang still generates misc:Built-Using for backward compatibility (in addition to misc:Static-Built-Using), so the field is filled for all three binaries.
• Testsuite: autopkgtest-pkg-go needs no debian/tests/: autodep8's Go support (/usr/share/autodep8/support/go/detect matches golang-any in Build-Depends, generate emits Test-Command: /usr/bin/dh_golang_autopkgtest) supplies the test, and @builddeps@ installs the <!nocheck> test dependency, so no test setup is missing.
• Standards-Version: 4.7.4 against Policy 4.7.4.1: current enough (first two components match). source/format is 3.0 (quilt); the changelog's 2.0.0-1 entry is well-formed and the version is a plausible new-upstream release.
• The man page documents only options that exist: every -flag in secsipidx.1 is registered by registerFlags in main.go.
• uscan found the packaged version as the newest upstream release (upstream 2.0.0, packaged 2.0.0).

• I could not run dpkg/apt, so I did not observe how the libsecsipid2 Breaks against libsecsipid1t64 is resolved in practice (removal of libsecsipid1t64 and kamailio-secsipid-modules, or a refused/hheld upgrade); the relationship is a defect either way.
• I did not build, so I did not check whether -L/usr/lib from the .pc file is harmless at link time on multiarch systems (the linker normally also searches the multiarch directory); the metadata is wrong regardless.

None.