Print errors on stderr

This makes a start on fixing https://github.com/Jguer/yay/issues/715
It is by no means a complete solution, but instead a start

callbacks.go

@@ -62,12 +62,12 @@ func questionCallback(question alpm.QuestionAny) {
 		numberBuf, overflow, err := reader.ReadLine()
 
 		if err != nil {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 			break
 		}
 
 		if overflow {
-			fmt.Println("Input too long")
+			fmt.Fprintln(os.Stderr, "Input too long")
 			continue
 		}
 
@@ -77,12 +77,12 @@ func questionCallback(question alpm.QuestionAny) {
 
 		num, err := strconv.Atoi(string(numberBuf))
 		if err != nil {
-			fmt.Printf("%s invalid number: %s\n", red("error:"), string(numberBuf))
+			fmt.Fprintf(os.Stderr, "%s invalid number: %s\n", red("error:"), string(numberBuf))
 			continue
 		}
 
 		if num < 1 || num > size {
-			fmt.Printf("%s invalid value: %d is not between %d and %d\n", red("error:"), num, 1, size)
+			fmt.Fprintf(os.Stderr, "%s invalid value: %d is not between %d and %d\n", red("error:"), num, 1, size)
 			continue
 		}
 

clean.go

@@ -207,14 +207,14 @@ func cleanAfter(bases []Base) {
 			fmt.Printf(bold(cyan("::")+" Cleaning (%d/%d): %s\n"), i+1, len(bases), cyan(dir))
 			_, stderr, err := capture(passToGit(dir, "reset", "--hard", "HEAD"))
 			if err != nil {
-				fmt.Printf("error resetting %s: %s", base.String(), stderr)
+				fmt.Fprintf(os.Stderr, "error resetting %s: %s", base.String(), stderr)
 			}
 
 			show(passToGit(dir, "clean", "-fx"))
 		} else {
 			fmt.Printf(bold(cyan("::")+" Deleting (%d/%d): %s\n"), i+1, len(bases), cyan(dir))
 			if err := os.RemoveAll(dir); err != nil {
-				fmt.Println(err)
+				fmt.Fprintln(os.Stderr, err)
 			}
 		}
 	}
@@ -225,7 +225,7 @@ func cleanBuilds(bases []Base) {
 		dir := filepath.Join(config.BuildDir, base.Pkgbase())
 		fmt.Printf(bold(cyan("::")+" Deleting (%d/%d): %s\n"), i+1, len(bases), cyan(dir))
 		if err := os.RemoveAll(dir); err != nil {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 		}
 	}
 }

cmd.go

@@ -328,8 +328,8 @@ func displayNumberMenu(pkgS []string) (err error) {
 	}
 
 	if aurErr != nil {
-		fmt.Printf("Error during AUR search: %s\n", aurErr)
-		fmt.Println("Showing repo packages only")
+		fmt.Fprintf(os.Stderr, "Error during AUR search: %s\n", aurErr)
+		fmt.Fprintln(os.Stderr, "Showing repo packages only")
 	}
 
 	fmt.Println(bold(green(arrow + " Packages to install (eg: 1 2 3, 1-3 or ^4)")))

config.go

@@ -214,7 +214,7 @@ func editor() (string, []string) {
 	case config.Editor != "":
 		editor, err := exec.LookPath(config.Editor)
 		if err != nil {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 		} else {
 			return editor, strings.Fields(config.EditorFlags)
 		}
@@ -223,7 +223,7 @@ func editor() (string, []string) {
 		editorArgs := strings.Fields(os.Getenv("EDITOR"))
 		editor, err := exec.LookPath(editorArgs[0])
 		if err != nil {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 		} else {
 			return editor, editorArgs[1:]
 		}
@@ -232,21 +232,21 @@ func editor() (string, []string) {
 		editorArgs := strings.Fields(os.Getenv("VISUAL"))
 		editor, err := exec.LookPath(editorArgs[0])
 		if err != nil {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 		} else {
 			return editor, editorArgs[1:]
 		}
 		fallthrough
 	default:
-		fmt.Println()
-		fmt.Println(bold(red(arrow)), bold(cyan("$EDITOR")), bold("is not set"))
-		fmt.Println(bold(red(arrow)) + bold(" Please add ") + bold(cyan("$EDITOR")) + bold(" or ") + bold(cyan("$VISUAL")) + bold(" to your environment variables."))
+		fmt.Fprintln(os.Stderr)
+		fmt.Fprintln(os.Stderr, bold(red(arrow)), bold(cyan("$EDITOR")), bold("is not set"))
+		fmt.Fprintln(os.Stderr, bold(red(arrow))+bold(" Please add ")+bold(cyan("$EDITOR"))+bold(" or ")+bold(cyan("$VISUAL"))+bold(" to your environment variables."))
 
 		for {
 			fmt.Print(green(bold(arrow + " Edit PKGBUILD with: ")))
 			editorInput, err := getInput("")
 			if err != nil {
-				fmt.Println(err)
+				fmt.Fprintln(os.Stderr, err)
 				continue
 			}
 
@@ -254,7 +254,7 @@ func editor() (string, []string) {
 
 			editor, err := exec.LookPath(editorArgs[0])
 			if err != nil {
-				fmt.Println(err)
+				fmt.Fprintln(os.Stderr, err)
 				continue
 			}
 			return editor, editorArgs[1:]
@@ -318,7 +318,7 @@ func (config Configuration) String() string {
 	enc := json.NewEncoder(&buf)
 	enc.SetIndent("", "\t")
 	if err := enc.Encode(config); err != nil {
-		fmt.Println(err)
+		fmt.Fprintln(os.Stderr, err)
 	}
 	return buf.String()
 }

depCheck.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"os"
 	"strings"
 	"sync"
 
@@ -74,23 +75,23 @@ func (ds *depSolver) CheckMissing() error {
 		return nil
 	}
 
-	fmt.Println(bold(red(arrow+" Error: ")) + "Could not find all required packages:")
+	fmt.Fprintln(os.Stderr, bold(red(arrow+" Error: "))+"Could not find all required packages:")
 	for dep, trees := range missing.Missing {
 		for _, tree := range trees {
 
-			fmt.Print("    ", cyan(dep))
+			fmt.Fprint(os.Stderr, "    ", cyan(dep))
 
 			if len(tree) == 0 {
-				fmt.Print(" (Target")
+				fmt.Fprint(os.Stderr, " (Target")
 			} else {
-				fmt.Print(" (Wanted by: ")
+				fmt.Fprint(os.Stderr, " (Wanted by: ")
 				for n := 0; n < len(tree)-1; n++ {
-					fmt.Print(cyan(tree[n]), " -> ")
+					fmt.Fprint(os.Stderr, cyan(tree[n]), " -> ")
 				}
-				fmt.Print(cyan(tree[len(tree)-1]))
+				fmt.Fprint(os.Stderr, cyan(tree[len(tree)-1]))
 			}
 
-			fmt.Println(")")
+			fmt.Fprintln(os.Stderr, ")")
 		}
 	}
 
@@ -263,11 +264,11 @@ func (ds *depSolver) CheckConflicts() (mapStringSet, error) {
 
 	formatConflicts := func(conflicts mapStringSet, inner bool, s string) {
 		if len(conflicts) != 0 {
-			fmt.Println()
+			fmt.Fprintln(os.Stderr)
 			if inner {
-				fmt.Println(bold(red(arrow)), bold("Inner conflicts found:"))
+				fmt.Fprintln(os.Stderr, bold(red(arrow)), bold("Inner conflicts found:"))
 			} else {
-				fmt.Println(bold(red(arrow)), bold("Package conflicts found:"))
+				fmt.Fprintln(os.Stderr, bold(red(arrow)), bold("Package conflicts found:"))
 			}
 
 			printConflict := func(name string, pkgs stringSet) {
@@ -277,7 +278,7 @@ func (ds *depSolver) CheckConflicts() (mapStringSet, error) {
 				}
 				str = strings.TrimSuffix(str, ",")
 
-				fmt.Println(str)
+				fmt.Fprintln(os.Stderr, str)
 			}
 
 			for _, pkg := range ds.Repo {
@@ -318,9 +319,9 @@ func (ds *depSolver) CheckConflicts() (mapStringSet, error) {
 				return nil, fmt.Errorf("Package conflicts can not be resolved with noconfirm, aborting")
 			}
 
-			fmt.Println()
-			fmt.Println(bold(red(arrow)), bold("Conflicting packages will have to be confirmed manually"))
-			fmt.Println()
+			fmt.Fprintln(os.Stderr)
+			fmt.Fprintln(os.Stderr, bold(red(arrow)), bold("Conflicting packages will have to be confirmed manually"))
+			fmt.Fprintln(os.Stderr)
 		}
 	}
 

download.go

@@ -165,11 +165,11 @@ func getPkgbuilds(pkgs []string) error {
 			name := base.Pkgbase()
 			_, err = os.Stat(filepath.Join(wd, name))
 			if err != nil && !os.IsNotExist(err) {
-				fmt.Println(bold(red(smallArrow)), err)
+				fmt.Fprintln(os.Stderr, bold(red(smallArrow)), err)
 				continue
 			} else if os.IsNotExist(err) || cmdArgs.existsArg("f", "force") || shouldUseGit(filepath.Join(wd, name)) {
 				if err = os.RemoveAll(filepath.Join(wd, name)); err != nil {
-					fmt.Println(bold(red(smallArrow)), err)
+					fmt.Fprintln(os.Stderr, bold(red(smallArrow)), err)
 					continue
 				}
 			} else {
@@ -249,11 +249,11 @@ func getPkgbuildsfromABS(pkgs []string, path string) (bool, error) {
 
 		_, err = os.Stat(filepath.Join(path, name))
 		if err != nil && !os.IsNotExist(err) {
-			fmt.Println(bold(red(smallArrow)), err)
+			fmt.Fprintln(os.Stderr, bold(red(smallArrow)), err)
 			continue
 		} else if os.IsNotExist(err) || cmdArgs.existsArg("f", "force") {
 			if err = os.RemoveAll(filepath.Join(path, name)); err != nil {
-				fmt.Println(bold(red(smallArrow)), err)
+				fmt.Fprintln(os.Stderr, bold(red(smallArrow)), err)
 				continue
 			}
 		} else {

exec.go

@@ -47,7 +47,7 @@ func updateSudo() {
 	for {
 		err := show(exec.Command("sudo", "-v"))
 		if err != nil {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 		} else {
 			break
 		}

install.go

@@ -434,9 +434,9 @@ nextpkg:
 
 	if len(incompatible) > 0 {
 		fmt.Println()
-		fmt.Print(bold(yellow(arrow)) + " The following packages are not compatible with your architecture:")
+		fmt.Print(bold(yellow(arrow))+" The following packages are not compatible with your architecture:")
 		for pkg := range incompatible {
-			fmt.Print("  " + cyan((basesMap[pkg].String())))
+			fmt.Print("  "+cyan(basesMap[pkg].String()))
 		}
 
 		fmt.Println()
@@ -763,7 +763,7 @@ func parseSrcinfoFiles(bases []Base, errIsFatal bool) (map[string]*gosrc.Srcinfo
 		pkgbuild, err := gosrc.ParseFile(filepath.Join(dir, ".SRCINFO"))
 		if err != nil {
 			if !errIsFatal {
-				fmt.Printf("failed to parse %s -- skipping: %s\n", base.String(), err)
+				fmt.Fprintf(os.Stderr, "failed to parse %s -- skipping: %s\n", base.String(), err)
 				continue
 			}
 			return nil, fmt.Errorf("failed to parse %s: %s", base.String(), err)
@@ -1057,7 +1057,7 @@ func buildInstallPkgbuilds(ds *depSolver, srcinfos map[string]*gosrc.Srcinfo, pa
 
 		err = saveVCSInfo()
 		if err != nil {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 		}
 
 		if len(depArguments.targets) > 0 {

main.go

@@ -184,7 +184,7 @@ func initAlpmHandle() error {
 func exitOnError(err error) {
 	if err != nil {
 		if str := err.Error(); str != "" {
-			fmt.Println(str)
+			fmt.Fprintln(os.Stderr, str)
 		}
 		cleanup()
 		os.Exit(1)
@@ -194,7 +194,7 @@ func exitOnError(err error) {
 func cleanup() int {
 	if alpmHandle != nil {
 		if err := alpmHandle.Release(); err != nil {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 			return 1
 		}
 	}
@@ -204,7 +204,7 @@ func cleanup() int {
 
 func main() {
 	if 0 == os.Geteuid() {
-		fmt.Println("Please avoid running yay as root/sudo.")
+		fmt.Fprintln(os.Stderr, "Please avoid running yay as root/sudo.")
 	}
 
 	exitOnError(setPaths())

print.go

@@ -371,7 +371,7 @@ outer:
 			}
 		}
 
-		fmt.Println(red(bold("error:")), "package '"+pkg+"' was not found")
+		fmt.Fprintln(os.Stderr, red(bold("error:")), "package '"+pkg+"' was not found")
 		missing = true
 	}
 
@@ -395,7 +395,7 @@ func (item item) print(buildTime time.Time) {
 	date, err := time.Parse(time.RFC1123Z, item.PubDate)
 
 	if err != nil {
-		fmt.Println(err)
+		fmt.Fprintln(os.Stderr, err)
 	} else {
 		fd = formatTime(int(date.Unix()))
 		if _, double, _ := cmdArgs.getArg("news", "w"); !double && !buildTime.IsZero() {
@@ -546,7 +546,7 @@ func providerMenu(dep string, providers providers) *rpc.Pkg {
 		size++
 	}
 
-	fmt.Println(str)
+	fmt.Fprintln(os.Stderr, str)
 
 	for {
 		fmt.Print("\nEnter a number (default=1): ")
@@ -560,12 +560,12 @@ func providerMenu(dep string, providers providers) *rpc.Pkg {
 		numberBuf, overflow, err := reader.ReadLine()
 
 		if err != nil {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 			break
 		}
 
 		if overflow {
-			fmt.Println("Input too long")
+			fmt.Fprintln(os.Stderr, "Input too long")
 			continue
 		}
 
@@ -575,12 +575,12 @@ func providerMenu(dep string, providers providers) *rpc.Pkg {
 
 		num, err := strconv.Atoi(string(numberBuf))
 		if err != nil {
-			fmt.Printf("%s invalid number: %s\n", red("error:"), string(numberBuf))
+			fmt.Fprintf(os.Stderr, "%s invalid number: %s\n", red("error:"), string(numberBuf))
 			continue
 		}
 
 		if num < 1 || num > size {
-			fmt.Printf("%s invalid value: %d is not between %d and %d\n", red("error:"), num, 1, size)
+			fmt.Fprintf(os.Stderr, "%s invalid value: %d is not between %d and %d\n", red("error:"), num, 1, size)
 			continue
 		}
 

query.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"os"
 	"sort"
 	"strings"
 	"sync"
@@ -192,8 +193,8 @@ func syncSearch(pkgS []string) (err error) {
 	}
 
 	if aurErr != nil {
-		fmt.Printf("Error during AUR search: %s\n", aurErr)
-		fmt.Println("Showing Repo packages only")
+		fmt.Fprintf(os.Stderr, "Error during AUR search: %s\n", aurErr)
+		fmt.Fprintln(os.Stderr, "Showing Repo packages only")
 	}
 
 	return nil
@@ -220,7 +221,7 @@ func syncInfo(pkgS []string) (err error) {
 		info, err = aurInfoPrint(noDb)
 		if err != nil {
 			missing = true
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 		}
 	}