diff --git a/src/cmd/link/internal/amd64/asm.go b/src/cmd/link/internal/amd64/asm.go
index c5909993fc..2e1791fdb2 100644
--- a/src/cmd/link/internal/amd64/asm.go
+++ b/src/cmd/link/internal/amd64/asm.go
@@ -102,7 +102,7 @@ func adddynrel(ctxt *ld.Link, s *ld.Symbol, r *ld.Reloc) bool {
 	switch r.Type {
 	default:
 		if r.Type >= 256 {
-			ld.Errorf(s, "unexpected relocation type %d", r.Type)
+			ld.Errorf(s, "unexpected relocation type %d (%s)", r.Type, ld.RelocName(r.Type))
 			return false
 		}
 
@@ -445,7 +445,7 @@ func machoreloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) int {
 
 	if rs.Type == ld.SHOSTOBJ || r.Type == objabi.R_PCREL || r.Type == objabi.R_GOTPCREL {
 		if rs.Dynid < 0 {
-			ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Type, rs.Type)
+			ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Type, rs.Type)
 			return -1
 		}
 
@@ -454,7 +454,7 @@ func machoreloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) int {
 	} else {
 		v = uint32(rs.Sect.Extnum)
 		if v == 0 {
-			ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Sect.Name, rs.Type, rs.Type)
+			ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Sect.Name, rs.Type, rs.Type)
 			return -1
 		}
 	}
@@ -507,7 +507,7 @@ func pereloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) bool {
 	rs := r.Xsym
 
 	if rs.Dynid < 0 {
-		ld.Errorf(s, "reloc %d (%s) to non-coff symbol %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Type, rs.Type)
+		ld.Errorf(s, "reloc %d (%s) to non-coff symbol %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Type, rs.Type)
 		return false
 	}
 
diff --git a/src/cmd/link/internal/arm/asm.go b/src/cmd/link/internal/arm/asm.go
index 2fc9329b61..20827817a7 100644
--- a/src/cmd/link/internal/arm/asm.go
+++ b/src/cmd/link/internal/arm/asm.go
@@ -118,7 +118,7 @@ func adddynrel(ctxt *ld.Link, s *ld.Symbol, r *ld.Reloc) bool {
 	switch r.Type {
 	default:
 		if r.Type >= 256 {
-			ld.Errorf(s, "unexpected relocation type %d", r.Type)
+			ld.Errorf(s, "unexpected relocation type %d (%s)", r.Type, ld.RelocName(r.Type))
 			return false
 		}
 
@@ -363,7 +363,7 @@ func machoreloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) int {
 
 	if rs.Type == ld.SHOSTOBJ || r.Type == objabi.R_CALLARM {
 		if rs.Dynid < 0 {
-			ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Type, rs.Type)
+			ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Type, rs.Type)
 			return -1
 		}
 
@@ -372,7 +372,7 @@ func machoreloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) int {
 	} else {
 		v = uint32(rs.Sect.Extnum)
 		if v == 0 {
-			ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Sect.Name, rs.Type, rs.Type)
+			ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Sect.Name, rs.Type, rs.Type)
 			return -1
 		}
 	}
@@ -481,7 +481,7 @@ func trampoline(ctxt *ld.Link, r *ld.Reloc, s *ld.Symbol) {
 			r.Done = 0
 		}
 	default:
-		ld.Errorf(s, "trampoline called with non-jump reloc: %v", r.Type)
+		ld.Errorf(s, "trampoline called with non-jump reloc: %d (%s)", r.Type, ld.RelocName(r.Type))
 	}
 }
 
diff --git a/src/cmd/link/internal/arm64/asm.go b/src/cmd/link/internal/arm64/asm.go
index 8d3c6fcb57..1e77431ca4 100644
--- a/src/cmd/link/internal/arm64/asm.go
+++ b/src/cmd/link/internal/arm64/asm.go
@@ -158,7 +158,7 @@ func machoreloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) int {
 	// UNSIGNED relocation at all.
 	if rs.Type == ld.SHOSTOBJ || r.Type == objabi.R_CALLARM64 || r.Type == objabi.R_ADDRARM64 || r.Type == objabi.R_ADDR {
 		if rs.Dynid < 0 {
-			ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Type, rs.Type)
+			ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Type, rs.Type)
 			return -1
 		}
 
@@ -167,7 +167,7 @@ func machoreloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) int {
 	} else {
 		v = uint32(rs.Sect.Extnum)
 		if v == 0 {
-			ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Sect.Name, rs.Type, rs.Type)
+			ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Sect.Name, rs.Type, rs.Type)
 			return -1
 		}
 	}
diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 691e74cc97..c096338232 100644
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -432,7 +432,7 @@ func relocsym(ctxt *Link, s *Symbol) {
 		// shared libraries, and Solaris needs it always
 		if Headtype != objabi.Hsolaris && r.Sym != nil && r.Sym.Type == SDYNIMPORT && !ctxt.DynlinkingGo() {
 			if !(SysArch.Family == sys.PPC64 && Linkmode == LinkExternal && r.Sym.Name == ".TOC.") {
-				Errorf(s, "unhandled relocation for %s (type %d (%s) rtype %d (%s))", r.Sym.Name, r.Sym.Type, r.Sym.Type, r.Type, r.Type)
+				Errorf(s, "unhandled relocation for %s (type %d (%s) rtype %d (%s))", r.Sym.Name, r.Sym.Type, r.Sym.Type, r.Type, RelocName(r.Type))
 			}
 		}
 		if r.Sym != nil && r.Sym.Type != STLSBSS && r.Type != objabi.R_WEAKADDROFF && !r.Sym.Attr.Reachable() {
@@ -465,7 +465,7 @@ func relocsym(ctxt *Link, s *Symbol) {
 				o = int64(ctxt.Arch.ByteOrder.Uint64(s.P[off:]))
 			}
 			if Thearch.Archreloc(ctxt, r, s, &o) < 0 {
-				Errorf(s, "unknown reloc to %v: %v", r.Sym.Name, r.Type)
+				Errorf(s, "unknown reloc to %v: %d (%s)", r.Sym.Name, r.Type, RelocName(r.Type))
 			}
 
 		case objabi.R_TLS_LE:
@@ -714,7 +714,7 @@ func relocsym(ctxt *Link, s *Symbol) {
 			if r.Sym != nil {
 				nam = r.Sym.Name
 			}
-			fmt.Printf("relocate %s %#x (%#x+%#x, size %d) => %s %#x +%#x [type %d/%d, %x]\n", s.Name, s.Value+int64(off), s.Value, r.Off, r.Siz, nam, Symaddr(r.Sym), r.Add, r.Type, r.Variant, o)
+			fmt.Printf("relocate %s %#x (%#x+%#x, size %d) => %s %#x +%#x [type %d (%s)/%d, %x]\n", s.Name, s.Value+int64(off), s.Value, r.Off, r.Siz, nam, Symaddr(r.Sym), r.Add, r.Type, RelocName(r.Type), r.Variant, o)
 		}
 		switch siz {
 		default:
@@ -828,7 +828,7 @@ func dynrelocsym(ctxt *Link, s *Symbol) {
 				Errorf(s, "dynamic relocation to unreachable symbol %s", r.Sym.Name)
 			}
 			if !Thearch.Adddynrel(ctxt, s, r) {
-				Errorf(s, "unsupported dynamic relocation for symbol %s (type=%d (%s) stype=%d (%s))", r.Sym.Name, r.Type, r.Type, r.Sym.Type, r.Sym.Type)
+				Errorf(s, "unsupported dynamic relocation for symbol %s (type=%d (%s) stype=%d (%s))", r.Sym.Name, r.Type, RelocName(r.Type), r.Sym.Type, r.Sym.Type)
 			}
 		}
 	}
diff --git a/src/cmd/link/internal/ld/elf.go b/src/cmd/link/internal/ld/elf.go
index 9ac55ada1d..2c3f99b756 100644
--- a/src/cmd/link/internal/ld/elf.go
+++ b/src/cmd/link/internal/ld/elf.go
@@ -1812,13 +1812,13 @@ func elfrelocsect(ctxt *Link, sect *Section, syms []*Symbol) {
 				continue
 			}
 			if r.Xsym.ElfsymForReloc() == 0 {
-				Errorf(sym, "reloc %d (%s) to non-elf symbol %s (outer=%s) %d (%s)", r.Type, r.Type, r.Sym.Name, r.Xsym.Name, r.Sym.Type, r.Sym.Type)
+				Errorf(sym, "reloc %d (%s) to non-elf symbol %s (outer=%s) %d (%s)", r.Type, RelocName(r.Type), r.Sym.Name, r.Xsym.Name, r.Sym.Type, r.Sym.Type)
 			}
 			if !r.Xsym.Attr.Reachable() {
-				Errorf(sym, "unreachable reloc %v target %v", r.Type, r.Xsym.Name)
+				Errorf(sym, "unreachable reloc %d (%s) target %v", r.Type, RelocName(r.Type), r.Xsym.Name)
 			}
 			if Thearch.Elfreloc1(ctxt, r, int64(uint64(sym.Value+int64(r.Off))-sect.Vaddr)) < 0 {
-				Errorf(sym, "unsupported obj reloc %d (%s)/%d to %s", r.Type, r.Type, r.Siz, r.Sym.Name)
+				Errorf(sym, "unsupported obj reloc %d (%s)/%d to %s", r.Type, RelocName(r.Type), r.Siz, r.Sym.Name)
 			}
 		}
 	}
diff --git a/src/cmd/link/internal/ld/link.go b/src/cmd/link/internal/ld/link.go
index 302364c299..857957afb0 100644
--- a/src/cmd/link/internal/ld/link.go
+++ b/src/cmd/link/internal/ld/link.go
@@ -330,3 +330,47 @@ const (
 	RV_CHECK_OVERFLOW RelocVariant = 1 << 7
 	RV_TYPE_MASK      RelocVariant = RV_CHECK_OVERFLOW - 1
 )
+
+func RelocName(r objabi.RelocType) string {
+	// We didn't have some relocation types at Go1.4.
+	// Uncomment code when we include those in bootstrap code.
+
+	switch {
+	case r >= 512: // Mach-O
+		// nr := (r - 512)>>1
+		// switch SysArch.Family {
+		// case sys.AMD64:
+		// 	return macho.RelocTypeX86_64(nr).String()
+		// case sys.ARM:
+		// 	return macho.RelocTypeARM(nr).String()
+		// case sys.ARM64:
+		// 	return macho.RelocTypeARM64(nr).String()
+		// case sys.I386:
+		// 	return macho.RelocTypeGeneric(nr).String()
+		// default:
+		// 	panic("unreachable")
+		// }
+	case r >= 256: // ELF
+		nr := r - 256
+		switch SysArch.Family {
+		case sys.AMD64:
+			return elf.R_X86_64(nr).String()
+		case sys.ARM:
+			return elf.R_ARM(nr).String()
+		case sys.ARM64:
+			return elf.R_AARCH64(nr).String()
+		case sys.I386:
+			return elf.R_386(nr).String()
+		case sys.MIPS, sys.MIPS64:
+			// return elf.R_MIPS(nr).String()
+		case sys.PPC64:
+			// return elf.R_PPC64(nr).String()
+		case sys.S390X:
+			// return elf.R_390(nr).String()
+		default:
+			panic("unreachable")
+		}
+	}
+
+	return r.String()
+}
diff --git a/src/cmd/link/internal/ld/macho.go b/src/cmd/link/internal/ld/macho.go
index ccdbc54f66..3997cfb844 100644
--- a/src/cmd/link/internal/ld/macho.go
+++ b/src/cmd/link/internal/ld/macho.go
@@ -930,10 +930,10 @@ func machorelocsect(ctxt *Link, sect *Section, syms []*Symbol) {
 				continue
 			}
 			if !r.Xsym.Attr.Reachable() {
-				Errorf(sym, "unreachable reloc %v target %v", r.Type, r.Xsym.Name)
+				Errorf(sym, "unreachable reloc %d (%s) target %v", r.Type, RelocName(r.Type), r.Xsym.Name)
 			}
 			if Thearch.Machoreloc1(sym, r, int64(uint64(sym.Value+int64(r.Off))-sect.Vaddr)) < 0 {
-				Errorf(sym, "unsupported obj reloc %v/%d to %s", r.Type, r.Siz, r.Sym.Name)
+				Errorf(sym, "unsupported obj reloc %d (%s)/%d to %s", r.Type, RelocName(r.Type), r.Siz, r.Sym.Name)
 			}
 		}
 	}
diff --git a/src/cmd/link/internal/ld/pe.go b/src/cmd/link/internal/ld/pe.go
index 171fa6da6e..7d17a6471d 100644
--- a/src/cmd/link/internal/ld/pe.go
+++ b/src/cmd/link/internal/ld/pe.go
@@ -882,10 +882,10 @@ func perelocsect(ctxt *Link, sect *Section, syms []*Symbol, base uint64) int {
 			}
 
 			if r.Xsym.Dynid < 0 {
-				Errorf(sym, "reloc %d (%s) to non-coff symbol %s (outer=%s) %d (%s)", r.Type, r.Type, r.Sym.Name, r.Xsym.Name, r.Sym.Type, r.Sym.Type)
+				Errorf(sym, "reloc %d (%s) to non-coff symbol %s (outer=%s) %d (%s)", r.Type, RelocName(r.Type), r.Sym.Name, r.Xsym.Name, r.Sym.Type, r.Sym.Type)
 			}
 			if !Thearch.PEreloc1(sym, r, int64(uint64(sym.Value+int64(r.Off))-base)) {
-				Errorf(sym, "unsupported obj reloc %d (%s)/%d to %s", r.Type, r.Type, r.Siz, r.Sym.Name)
+				Errorf(sym, "unsupported obj reloc %d (%s)/%d to %s", r.Type, RelocName(r.Type), r.Siz, r.Sym.Name)
 			}
 
 			relocs++
diff --git a/src/cmd/link/internal/ppc64/asm.go b/src/cmd/link/internal/ppc64/asm.go
index ee4e218125..b2f040b5ba 100644
--- a/src/cmd/link/internal/ppc64/asm.go
+++ b/src/cmd/link/internal/ppc64/asm.go
@@ -252,7 +252,7 @@ func adddynrel(ctxt *ld.Link, s *ld.Symbol, r *ld.Reloc) bool {
 	switch r.Type {
 	default:
 		if r.Type >= 256 {
-			ld.Errorf(s, "unexpected relocation type %d", r.Type)
+			ld.Errorf(s, "unexpected relocation type %d (%s)", r.Type, ld.RelocName(r.Type))
 			return false
 		}
 
@@ -581,7 +581,7 @@ func trampoline(ctxt *ld.Link, r *ld.Reloc, s *ld.Symbol) {
 			r.Done = 0
 		}
 	default:
-		ld.Errorf(s, "trampoline called with non-jump reloc: %v", r.Type)
+		ld.Errorf(s, "trampoline called with non-jump reloc: %d (%s)", r.Type, ld.RelocName(r.Type))
 	}
 }
 
diff --git a/src/cmd/link/internal/x86/asm.go b/src/cmd/link/internal/x86/asm.go
index 157b426971..dc60381d14 100644
--- a/src/cmd/link/internal/x86/asm.go
+++ b/src/cmd/link/internal/x86/asm.go
@@ -170,7 +170,7 @@ func adddynrel(ctxt *ld.Link, s *ld.Symbol, r *ld.Reloc) bool {
 	switch r.Type {
 	default:
 		if r.Type >= 256 {
-			ld.Errorf(s, "unexpected relocation type %d", r.Type)
+			ld.Errorf(s, "unexpected relocation type %d (%s)", r.Type, ld.RelocName(r.Type))
 			return false
 		}
 
@@ -416,7 +416,7 @@ func machoreloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) int {
 
 	if rs.Type == ld.SHOSTOBJ {
 		if rs.Dynid < 0 {
-			ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Type, rs.Type)
+			ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Type, rs.Type)
 			return -1
 		}
 
@@ -425,7 +425,7 @@ func machoreloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) int {
 	} else {
 		v = uint32(rs.Sect.Extnum)
 		if v == 0 {
-			ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Sect.Name, rs.Type, rs.Type)
+			ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Sect.Name, rs.Type, rs.Type)
 			return -1
 		}
 	}
@@ -471,7 +471,7 @@ func pereloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) bool {
 	rs := r.Xsym
 
 	if rs.Dynid < 0 {
-		ld.Errorf(s, "reloc %d (%s) to non-coff symbol %s type=%d (%s)", r.Type, r.Type, rs.Name, rs.Type, rs.Type)
+		ld.Errorf(s, "reloc %d (%s) to non-coff symbol %s type=%d (%s)", r.Type, ld.RelocName(r.Type), rs.Name, rs.Type, rs.Type)
 		return false
 	}