Sign the dist as the last step before creating the archive. Take care not to modify/regenerate dist meta files or the manifest.

Error: Old SIGNATURE detected. Please inform the module author to regenerate SIGNATURE using Module::Signature version 0.82 or newer. gpg: Signature made Wed 29 Jul 2015 02:44:37 AM JST gpg: using DSA key CF797F34DDF0B149 gpg: Can't check signature: No public key --- SIGNATURE Wed Jul 29 20:53:06 2015 +++ @@ -1,21 +1,20 @@ -SHA1 19ac9eb1570ace4d76b4feed902e029b0bb68d16 .perlcriticrc SHA1 b256632dcce76559734ff0a23330d2898b7d3a3b COPYING.LIB -SHA1 4328fd1ba1ff044a91acabf824cee315b24dc21e Changes -SHA1 4b644b65694ee180312afd292bf553b484f97518 GMP.xs +SHA1 1cf958f89291813197aac3a1840f1e15dc902287 Changes +SHA1 ff4be8cde0ea41cb7efa95ec02febcd55deb6c11 GMP.xs SHA1 7b08e2399ff1482d96021f71e4387ca862da7051 INSTALL SHA1 505b15d429518390a904f67c0a16b30421b27513 LICENSE -SHA1 98f39e6c4dfe0886d39a2b1a6877869334575312 MANIFEST -SHA1 bc2fd4381ac3dfb582a4b701e3b1324dae0579c9 MANIFEST.bak -SHA1 3ffa3954cfd10271f9fa7eb8fc713efdda21f633 META.yml -SHA1 8833910c8afbb499bf36984a703ce41622e3f7a1 MYMETA.json -SHA1 72858ce082a8ea13438a335fca42a21df2e8e794 MYMETA.yml -SHA1 35d0daae8d7d0e3a1218bbcde6659343e6170475 Makefile.PL +SHA1 43c9a76575441ad2ace570c9d6cbbcbee59cb7de MANIFEST +SHA1 a84c9d9ceb94df42191fc894a9ba017d90e64111 META.yml +SHA1 1a5583fe80946ea907fc3cd3afbf369b872baf30 Makefile.PL SHA1 8281d135960d8d8ae696604566aa05dfdf9c01a1 README -SHA1 b84ddbd8781d1c773c2f6eaa2cb6b6473d7e7178 lib/Math/GMP.pm -SHA1 c6d5b40068571194f3d6718dad8d8f500e91498a t/00_signature.t -SHA1 362a396170f05654996585239de3e805d9e66ff6 t/01_gmppm.t -SHA1 6479bc4bcf09fb9876fc52e2c02a91d9452c3018 t/99_perlcritic.t -SHA1 9e5d32b76d38bf139b4798e16859fd484769fcf9 t/99_pod.t +SHA256 3e247767184b5761281d3b65fe3b37669b607ad2d93da26841818e5adca4d9f0 dist.ini +SHA1 85b1b2583e6dc03f8dcb2c991b57efbaa286e837 lib/Math/GMP.pm +SHA256 cf985bef9f8ab66b6de081f13480805a59a4c0d1fb5a9e039f0061e6df8f3ce2 t/00-compile.t +SHA1 dceb402561d528a998ac5b0bd8648cec99f3218b t/01_gmppm.t SHA1 46a33d87e8640e65dafb83b5e32ff5bed2e6ce73 t/99_spellcheck.t SHA1 762b0b761deaff9c2821400917698ded8983cc65 t/99_yaml.t SHA1 b47b081069df37efedcf7217ff66683deaa5fb14 typemap +SHA256 576bfcb745eb615592498b3c911ae340f233fe6e60842f21a1aaebef265366e7 weaver.ini +SHA256 0f8e88b7684e906a7ab56fc70362043a21178b17eee25ddb74c9ae70f1ecedf5 xt/release/cpan-changes.t +SHA256 32ca32af4808cf0d2e0c590d918bb0f51bc51d7934d32a6543a68f58a01c8292 xt/release/pod-syntax.t +SHA256 dc5efc57dfb75d237226e738436163cf52c61d724e2dc595d97d7b95a1196352 xt/release/trailing-space.t ==> MISMATCHED content between SIGNATURE and distribution files! <==

Add a META.json to the distribution. Your buildtool should be able to autogenerate it.