gnu: Add bitcoin-abc.

* gnu/packages/finance.scm (bitcoin-abc): New variable.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/finance.scm

@@ -1111,3 +1111,31 @@ information.")
     (description "This allows a Trezor hardware wallet to communicate to the
 Trezor wallet.")
     (license license:lgpl3+)))
+
+(define-public bitcoin-abc
+  (package
+    (inherit bitcoin-core)
+    (name "bitcoin-abc")
+    (version "0.19.8")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append "https://download.bitcoinabc.org/"
+                                  version "/linux/src/bitcoin-abc-"
+                                  version ".tar.gz"))
+              (sha256
+               (base32
+                "0ndvkxv5m8346bdhfqzgdiz1k9wyjycj05jp7daf9pml3cw79sz5"))))
+    (home-page "https://www.bitcoinabc.org/")
+    (synopsis "Bitcoin ABC peer-to-peer full node for the Bitcoin Cash protocol")
+    (description
+     "Bitcoin Cash brings sound money to the world, fulfilling the original
+promise of Bitcoin as Peer-to-Peer Electronic Cash.  Merchants and users are
+empowered with low fees and reliable confirmations is a digital currency that
+enables instant payments to anyone anywhere in the world.  It uses
+peer-to-peer technology to operate without central authority: managing
+transactions and issuing money are carried out collectively by the network.
+As a fork it implemented changes lowering the time between blocks and now
+offers confimations after less than 5 seconds and have significantly lower
+fees that BTC.  Bitcoin ABC is the reference implementation of the Bitcoin
+Cash protocol.  This package provides the Bitcoin Cash command line client and
+a client based on Qt.  This is a fork of Bitcoin Core.")))