Improve how vcvarsall is located

.github/workflows/fips.yml

@@ -58,7 +58,7 @@ jobs:
       fail-fast: false
       matrix:
         rust: [ stable ]
-        os: [ windows-2019, windows-2022 ]
+        os: [ windows-2019, windows-latest ]
         args:
           - --all-targets --features fips,unstable
           - --all-targets --features fips,bindgen,unstable

aws-lc-fips-sys/builder/cmake_builder.rs

@@ -162,6 +162,7 @@ impl CmakeBuilder {
         let script_path = self.manifest_dir.join("builder").join("printenv.bat");
         let result = test_command(script_path.as_os_str(), &[]);
         if !result.status {
+            eprintln!("{}", result.output);
             return Err("Failed to run vccarsall.bat.".to_owned());
         }
         let lines = result.output.lines();

aws-lc-fips-sys/builder/printenv.bat

@@ -1,7 +1,35 @@
 @echo off
+setlocal EnableDelayedExpansion
 for /f "usebackq tokens=* delims=" %%i in (`"%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe" -latest -property installationPath`) do (
-    set "VS_PATH=%%i"
+    set "VS_PATH=%%i\VC\Auxiliary\Build\"
+    echo FOUND: "!VS_PATH!"
+    goto FoundVS
 )
-call "%VS_PATH%\VC\Auxiliary\Build\vcvarsall.bat" x64
 
-set
+echo Visual Studio installation not found using vswhere. Searching in default directories...
+for /R "%ProgramFiles(x86)%\Microsoft Visual Studio" %%a in (vcvarsall.bat) do (
+    if exist "%%~fa" (
+        set "VS_PATH=%%~dpa"
+        echo FOUND: "!VS_PATH!"
+        goto FoundVS
+    )
+)
+echo vcvarsall.bat not found.
+goto End
+
+:FoundVS
+call "!VS_PATH!vcvarsall.bat" x64
+if !ERRORLEVEL! neq 0 (
+    echo Failed to set Visual Studio environment variables.
+    echo PATH: "!VS_PATH!vcvarsall.bat"
+    goto End
+)
+echo Visual Studio environment variables set for x64.
+
+set
+endlocal
+exit /b 0
+
+:End
+endlocal
+exit /b 1