Fail python_packages on --x-fast

So that we don't attempt to parse requirements specs and instead pass
them as is to monobase, i.e. `uv pip compile` for validation

pkg/dockerfile/fast_generator_test.go

@@ -1,6 +1,8 @@
 package dockerfile
 
 import (
+	"os"
+	"path"
 	"strings"
 	"testing"
 
@@ -10,11 +12,19 @@ import (
 	"github.com/replicate/cog/pkg/docker/dockertest"
 )
 
+func writeRequirements(t *testing.T, req string) string {
+	srcDir := t.TempDir()
+	reqFile := path.Join(srcDir, "requirements.txt")
+	err := os.WriteFile(reqFile, []byte(req), 0o644)
+	require.NoError(t, err)
+	return reqFile
+}
+
 func TestGenerate(t *testing.T) {
 	dir := t.TempDir()
 	build := config.Build{
-		PythonVersion:  "3.8",
-		PythonPackages: []string{"torch==2.5.1"},
+		PythonVersion:      "3.8",
+		PythonRequirements: writeRequirements(t, "torch==2.5.1"),
 	}
 	config := config.Config{
 		Build: &build,
@@ -55,11 +65,8 @@ func TestGenerate(t *testing.T) {
 func TestGenerateUVCacheMount(t *testing.T) {
 	dir := t.TempDir()
 	build := config.Build{
-		PythonVersion: "3.8",
-		PythonPackages: []string{
-			"torch==2.5.1",
-			"catboost==1.2.7",
-		},
+		PythonVersion:      "3.8",
+		PythonRequirements: writeRequirements(t, "torch==2.5.1\ncatboost==1.2.7"),
 	}
 	config := config.Config{
 		Build: &build,
@@ -142,10 +149,8 @@ func TestGenerateCUDA(t *testing.T) {
 func TestGeneratePythonPackages(t *testing.T) {
 	dir := t.TempDir()
 	build := config.Build{
-		PythonVersion: "3.8",
-		PythonPackages: []string{
-			"catboost==1.2.7",
-		},
+		PythonVersion:      "3.8",
+		PythonRequirements: writeRequirements(t, "catboost==1.2.7"),
 	}
 	config := config.Config{
 		Build: &build,
@@ -186,8 +191,8 @@ func TestGeneratePythonPackages(t *testing.T) {
 func TestGenerateVerboseEnv(t *testing.T) {
 	dir := t.TempDir()
 	build := config.Build{
-		PythonVersion:  "3.8",
-		PythonPackages: []string{"torch==2.5.1"},
+		PythonVersion:      "3.8",
+		PythonRequirements: writeRequirements(t, "torch==2.5.1"),
 	}
 	config := config.Config{
 		Build: &build,

pkg/requirements/requirements.go

@@ -1,85 +1,52 @@
 package requirements
 
 import (
-	"bufio"
 	"errors"
+	"fmt"
 	"os"
 	"path/filepath"
-	"sort"
 
 	"github.com/replicate/cog/pkg/config"
 )
 
 const REQUIREMENTS_FILE = "requirements.txt"
 
 func GenerateRequirements(tmpDir string, cfg *config.Config) (string, error) {
-	// Deduplicate packages between the requirements.txt and the python packages directive.
-	packageNames := make(map[string]string)
-
-	// Read the python packages configuration.
-	for _, requirement := range cfg.Build.PythonPackages {
-		packageName, err := config.PackageName(requirement)
-		if err != nil {
-			return "", err
-		}
-		packageNames[packageName] = requirement
+	if len(cfg.Build.PythonPackages) > 0 {
+		return "", fmt.Errorf("python_packages is no longer supported, use python_requirements instead")
 	}
 
-	// Read the python requirements.
-	if cfg.Build.PythonRequirements != "" {
-		fh, err := os.Open(cfg.Build.PythonRequirements)
-		if err != nil {
-			return "", err
-		}
-		scanner := bufio.NewScanner(fh)
-		for scanner.Scan() {
-			requirement := scanner.Text()
-			packageName, err := config.PackageName(requirement)
-			if err != nil {
-				return "", err
-			}
-			packageNames[packageName] = requirement
-		}
-	}
-
-	// If we don't have any packages skip further processing
-	if len(packageNames) == 0 {
+	// No Python requirements
+	if cfg.Build.PythonRequirements == "" {
 		return "", nil
 	}
 
-	// Sort the package names by alphabetical order.
-	keys := make([]string, 0, len(packageNames))
-	for k := range packageNames {
-		keys = append(keys, k)
-	}
-	sort.Strings(keys)
-
-	// Render the expected contents
-	requirementsContent := ""
-	for _, k := range keys {
-		requirementsContent += packageNames[k] + "\n"
+	bs, err := os.ReadFile(cfg.Build.PythonRequirements)
+	if err != nil {
+		return "", err
 	}
+	requirements := string(bs)
 
-	// Check against the old requirements contents
+	// Check against the old requirements
 	requirementsFile := filepath.Join(tmpDir, REQUIREMENTS_FILE)
-	_, err := os.Stat(requirementsFile)
-	if !errors.Is(err, os.ErrNotExist) {
-		bytes, err := os.ReadFile(requirementsFile)
+	if _, err := os.Stat(requirementsFile); err == nil {
+		bs, err = os.ReadFile(requirementsFile)
 		if err != nil {
 			return "", err
 		}
-		oldRequirementsContents := string(bytes)
-		if oldRequirementsContents == requirementsFile {
+		if string(bs) == requirements {
 			return requirementsFile, nil
 		}
+	} else if !errors.Is(err, os.ErrNotExist) {
+		return "", err
 	}
 
 	// Write out a new requirements file
-	err = os.WriteFile(requirementsFile, []byte(requirementsContent), 0o644)
+	err = os.WriteFile(requirementsFile, []byte(requirements), 0o644)
 	if err != nil {
 		return "", err
 	}
-	return requirementsFile, nil
+	return requirementsFile, err
 }
 
 func CurrentRequirements(tmpDir string) (string, error) {

pkg/requirements/requirements_test.go

@@ -1,6 +1,8 @@
 package requirements
 
 import (
+	"os"
+	"path"
 	"path/filepath"
 	"testing"
 
@@ -9,14 +11,31 @@ import (
 	"github.com/replicate/cog/pkg/config"
 )
 
-func TestGenerateRequirements(t *testing.T) {
+func TestPythonPackages(t *testing.T) {
 	tmpDir := t.TempDir()
 	build := config.Build{
 		PythonPackages: []string{"torch==2.5.1"},
 	}
 	config := config.Config{
 		Build: &build,
 	}
+	_, err := GenerateRequirements(tmpDir, &config)
+	require.ErrorContains(t, err, "python_packages is no longer supported, use python_requirements instead")
+}
+
+func TestPythonRequirements(t *testing.T) {
+	srcDir := t.TempDir()
+	reqFile := path.Join(srcDir, "requirements.txt")
+	err := os.WriteFile(reqFile, []byte("torch==2.5.1"), 0o644)
+	require.NoError(t, err)
+
+	build := config.Build{
+		PythonRequirements: reqFile,
+	}
+	config := config.Config{
+		Build: &build,
+	}
+	tmpDir := t.TempDir()
 	requirementsFile, err := GenerateRequirements(tmpDir, &config)
 	require.NoError(t, err)
 	require.Equal(t, filepath.Join(tmpDir, "requirements.txt"), requirementsFile)