Revert "cmd/geth, internal/flags: print envvar config source and bad names (#28119)"

This reverts commit c59e4a47dc.

cmd/geth/main.go

@@ -249,11 +249,7 @@ func init() {
 	app.Before = func(ctx *cli.Context) error {
 		maxprocs.Set() // Automatically set GOMAXPROCS to match Linux container CPU quota.
 		flags.MigrateGlobalFlags(ctx)
-		if err := debug.Setup(ctx); err != nil {
+		return debug.Setup(ctx)
-			return err
-		}
-		flags.CheckEnvVars(ctx, app.Flags, "GETH")
-		return nil
 	}
 	app.After = func(ctx *cli.Context) error {
 		debug.Exit()

internal/flags/helpers.go

@@ -20,11 +20,9 @@ import (
 	"fmt"
 	"os"
 	"regexp"
-	"sort"
 	"strings"
 
 	"github.com/ethereum/go-ethereum/internal/version"
-	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/mattn/go-isatty"
 	"github.com/urfave/cli/v2"
@@ -265,37 +263,3 @@ func AutoEnvVars(flags []cli.Flag, prefix string) {
 		}
 	}
 }
-
-// CheckEnvVars iterates over all the environment variables and checks if any of
-// them look like a CLI flag but is not consumed. This can be used to detect old
-// or mistyped names.
-func CheckEnvVars(ctx *cli.Context, flags []cli.Flag, prefix string) {
-	known := make(map[string]string)
-	for _, flag := range flags {
-		docflag, ok := flag.(cli.DocGenerationFlag)
-		if !ok {
-			continue
-		}
-		for _, envvar := range docflag.GetEnvVars() {
-			known[envvar] = flag.Names()[0]
-		}
-	}
-	keyvals := os.Environ()
-	sort.Strings(keyvals)
-
-	for _, keyval := range keyvals {
-		key := strings.Split(keyval, "=")[0]
-		if !strings.HasPrefix(key, prefix) {
-			continue
-		}
-		if flag, ok := known[key]; ok {
-			if ctx.Count(flag) > 0 {
-				log.Info("Config environment variable found", "envvar", key, "shadowedby", "--"+flag)
-			} else {
-				log.Info("Config environment variable found", "envvar", key)
-			}
-		} else {
-			log.Warn("Unknown config environment variable", "envvar", key)
-		}
-	}
-}