Do not override provides, instead append

.SRCINFO

@@ -1,7 +1,7 @@
 pkgbase = serd-git
 	pkgdesc = Lightweight C library for RDF syntax supporting reading / writing Turtle and NTriples (git version)
 	pkgver = 0.30.15.r1032.14f422f6
-	pkgrel = 1
+	pkgrel = 2
 	url = http://drobilla.net/software/serd/
 	arch = i686
 	arch = x86_64
@@ -20,4 +20,7 @@ pkgbase = serd-git
 	sha256sums = SKIP
 
 pkgname = serd-git
+	provides = serd
+	provides = serd=0.30.15
+	provides = serd-docs
 	provides = libserd-0.so

PKGBUILD

@@ -3,7 +3,7 @@
 _pkgname=serd
 pkgname=$_pkgname-git
 pkgver=0.30.15.r1032.14f422f6
-pkgrel=1
+pkgrel=2
 pkgdesc='Lightweight C library for RDF syntax supporting reading / writing Turtle and NTriples (git version)'
 arch=(i686 x86_64)
 url='http://drobilla.net/software/serd/'
@@ -32,7 +32,7 @@ check() {
 }
 
 package() {
-  provides=(libserd-0.so)
+  provides+=(libserd-0.so)
   meson install -C $_pkgname-build --destdir "$pkgdir"
   mv -v "$pkgdir"/usr/share/doc/{serd-0,$pkgname}
   install -vDm 644 $_pkgname/COPYING -t "$pkgdir"/usr/share/licenses/$pkgname