Handle bogus pager gracefully

go/store/util/outputpager/page_output.go

@@ -68,15 +68,18 @@ func Start() *Pager {
 		parts := strings.Fields(doltPager)
 		pagerPath, err = exec.LookPath(parts[0])
 		if err != nil {
-			d.Chk.NoError(err)
-		}
-		if len(parts) > 1 {
-			cmd = exec.Command(pagerPath, parts[1:]...)
+			// If the specified pager is not found, print an error and fall back to less or more
+			fmt.Fprintf(os.Stderr, "warning: specified pager '%s' not found, falling back to less or more\n", parts[0])
 		} else {
-			cmd = exec.Command(pagerPath)
+			if len(parts) > 1 {
+				cmd = exec.Command(pagerPath, parts[1:]...)
+			} else {
+				cmd = exec.Command(pagerPath)
+			}
 		}
-	} else {
-		// Fall back to less or more if DOLT_PAGER is not set
+	}
+
+	if cmd == nil {
 		pagerPath, err = exec.LookPath("less")
 		if err != nil {
 			pagerPath, err = exec.LookPath("more")

integration-tests/bats/pager.bats

@@ -36,3 +36,13 @@ export NO_COLOR=1
   [[ ! "$output" =~ "commit 17 abc" ]] || false
   [ "${#lines[@]}" -eq 3 ]
 }
+
+# bats test_tags=no_lambda
+@test "pager: gracefully exit when pager doesn't exist" {
+  skiponwindows "Need to install expect and make this script work on windows."
+  export DOLT_PAGER="foobar"
+
+  run expect $BATS_TEST_DIRNAME/pager.expect
+  [ "$status" -eq 0 ]
+  [[ "$output" =~ "warning: specified pager 'foobar' not found, falling back to less or more" ]] || false
+}