From ebaad6eb5ac6ac13607011ffe252beb96d3f3c9a Mon Sep 17 00:00:00 2001
From: Lucas Bajolet <lucas.bajolet@hashicorp.com>
Date: Mon, 17 Jul 2023 15:25:42 +0000
Subject: [PATCH] backport of commit f4eda950c2e1ec5a9f6c4e3a3d4e78bd7499583f

---
 hcl2template/plugin.go | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/hcl2template/plugin.go b/hcl2template/plugin.go
index 47cf4b40d..4a5c01866 100644
--- a/hcl2template/plugin.go
+++ b/hcl2template/plugin.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"log"
 	"runtime"
+	"strings"
 
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/packer-plugin-sdk/didyoumean"
@@ -77,6 +78,8 @@ func (cfg *PackerConfig) DetectPluginBinaries() hcl.Diagnostics {
 		return diags
 	}
 
+	uninstalledPlugins := map[string]string{}
+
 	for _, pluginRequirement := range pluginReqs {
 		sortedInstalls, err := pluginRequirement.ListInstallations(opts)
 		if err != nil {
@@ -88,11 +91,7 @@ func (cfg *PackerConfig) DetectPluginBinaries() hcl.Diagnostics {
 			continue
 		}
 		if len(sortedInstalls) == 0 {
-			diags = append(diags, &hcl.Diagnostic{
-				Severity: hcl.DiagError,
-				Summary:  fmt.Sprintf("no plugin installed for %s %v", pluginRequirement.Identifier, pluginRequirement.VersionConstraints.String()),
-				Detail:   "Did you run packer init for this project ?",
-			})
+			uninstalledPlugins[pluginRequirement.Identifier.String()] = pluginRequirement.VersionConstraints.String()
 			continue
 		}
 		log.Printf("[TRACE] Found the following %q installations: %v", pluginRequirement.Identifier, sortedInstalls)
@@ -108,6 +107,20 @@ func (cfg *PackerConfig) DetectPluginBinaries() hcl.Diagnostics {
 		}
 	}
 
+	if len(uninstalledPlugins) > 0 {
+		detailMessage := &strings.Builder{}
+		detailMessage.WriteString("The following plugins are required, but not installed:\n\n")
+		for pluginName, pluginVersion := range uninstalledPlugins {
+			fmt.Fprintf(detailMessage, "* %s %s\n", pluginName, pluginVersion)
+		}
+		detailMessage.WriteString("\nDid you run packer init for this project ?")
+		diags = append(diags, &hcl.Diagnostic{
+			Severity: hcl.DiagError,
+			Summary:  "Missing plugins",
+			Detail:   detailMessage.String(),
+		})
+	}
+
 	return diags
 }