cmd/go: add base.Error and base.Fatal

Many many places in the go command use

	base.Errorf("go: %v", err)

or

	base.Fatalf("go: %v", err)

Introduce Error(error) and Fatal(error) to do this
and update all call sites (global search and replace).

The new Error gives us the opportunity to unwrap
a multierror and add the go prefix to each line,
which is the motivation for this change.
(We want to start returning a multierror from LoadModFile
and LoadModGraph.)

For #57001.

Change-Id: I9613653b94808224146077c30d22f814d4e19eed
Reviewed-on: https://go-review.googlesource.com/c/go/+/499980
Auto-Submit: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/cmd/go/internal/modload/load.go b/src/cmd/go/internal/modload/load.go
index 8f1eb1098bd..0a06b1b1253 100644
--- a/src/cmd/go/internal/modload/load.go
+++ b/src/cmd/go/internal/modload/load.go
@@ -430,7 +430,7 @@ func LoadPackages(ctx context.Context, opts PackageOpts, patterns ...string) (ma
 			// preserve checksums for) additional entities from compatRS, which are
 			// only needed for compatibility with ld.TidyCompatibleVersion.
 			if err := modfetch.WriteGoSum(ctx, keep, mustHaveCompleteRequirements()); err != nil {
-				base.Fatalf("go: %v", err)
+				base.Fatal(err)
 			}
 		}
 	}
@@ -451,7 +451,7 @@ func LoadPackages(ctx context.Context, opts PackageOpts, patterns ...string) (ma
 
 	if !ExplicitWriteGoMod && opts.ResolveMissingImports {
 		if err := commitRequirements(ctx, WriteOpts{}); err != nil {
-			base.Fatalf("go: %v", err)
+			base.Fatal(err)
 		}
 	}
 
@@ -714,7 +714,7 @@ func ImportFromFiles(ctx context.Context, gofiles []string) {
 	tags := imports.Tags()
 	imports, testImports, err := imports.ScanFiles(gofiles, tags)
 	if err != nil {
-		base.Fatalf("go: %v", err)
+		base.Fatal(err)
 	}
 
 	loaded = loadFromRoots(ctx, loaderParams{
@@ -734,7 +734,7 @@ func ImportFromFiles(ctx context.Context, gofiles []string) {
 
 	if !ExplicitWriteGoMod {
 		if err := commitRequirements(ctx, WriteOpts{}); err != nil {
-			base.Fatalf("go: %v", err)
+			base.Fatal(err)
 		}
 	}
 }