2 files changed, 21 insertions, 8 deletions
diff --git a/etc/environments/default-clang.bat b/etc/environments/default-clang.bat
index c5929d5..5c03fbe 100644
--- a/etc/environments/default-clang.bat
+++ b/etc/environments/default-clang.bat
@@ -14,9 +14,9 @@ rem
 set "C=clang"
 set "CXX=clang++"
 
-rem If the MSVC variable is set, then set up the environment via the MSVC
-rem command prompt rather than letting Clang find some default (note that
-rem in the latter case, clang++ should be in PATH).
+rem If the MSVC and VCVARS variables are set, then set up the environment
+rem via the MSVC command prompt rather than letting Clang find some default
+rem (note that in the latter case, clang++ should be in PATH).
 rem
 rem Note also that MSVC_VER must always be set.
 
@@ -39,6 +39,7 @@ setlocal EnableExtensions EnableDelayedExpansion
 
 rem Based on target determine what we are building.
 rem
+set "VCVARS="
 set "MODE="
 if "_%1_" == "_x86_64-microsoft-win32-msvc%MSVC_VER%_" (
   set "VCVARS=%VCVARS64%"
@@ -59,8 +60,10 @@ if "_%1_" == "_x86_64-microsoft-win32-msvc%MSVC_VER%_" (
 )
 
 if not "_%MSVC%_" == "__" (
-  call "%MSVC%\%VCVARS%"
-  if errorlevel 1 goto error
+  if not "_%VCVARS%_" == "__" (
+    call "%MSVC%\%VCVARS%"
+    if errorlevel 1 goto error
+  )
 )
 
 %2 %3 %4 %5 %6 %7 %8 %9 cc config.c=%C% config.cxx=%CXX% %MODE%
diff --git a/etc/environments/default-msvc.bat b/etc/environments/default-msvc.bat
index fcb3155..381dc73 100644
--- a/etc/environments/default-msvc.bat
+++ b/etc/environments/default-msvc.bat
@@ -8,6 +8,11 @@ rem
 rem Environment setup script for C/C++ compilation with Visual Studio.
 rem
 
+rem If the MSVC and VCVARS variables are set, then set up the environment via
+rem the MSVC command prompt rather than letting build2 find the default.
+rem
+rem Note also that MSVC_VER must always be set.
+
 rem set "MSVC=C:\Program Files (x86)\Microsoft Visual Studio\2017\Community"
 rem set "MSVC_VER=14.1"
 
@@ -25,8 +30,9 @@ setlocal EnableExtensions EnableDelayedExpansion
 
 rem Based on target determine what we are building.
 rem
+set "VCVARS="
 if "_%1_" == "_x86_64-microsoft-win32-msvc%MSVC_VER%_" (
-  set "VCVARS=%VCVARS64%"
+  rem set "VCVARS=%VCVARS64%"
 ) else (
   if "_%1_" == "_i686-microsoft-win32-msvc%MSVC_VER%_" (
     set "VCVARS=%VCVARS32%"
@@ -40,8 +46,12 @@ if "_%1_" == "_x86_64-microsoft-win32-msvc%MSVC_VER%_" (
   )
 )
 
-call "%MSVC%\%VCVARS%"
-if errorlevel 1 goto error
+if not "_%MSVC%_" == "__" (
+  if not "_%VCVARS%_" == "__" (
+    call "%MSVC%\%VCVARS%"
+    if errorlevel 1 goto error
+  )
+)
 
 %2 %3 %4 %5 %6 %7 %8 %9 cc config.c=cl config.cxx=cl
 if errorlevel 1 goto error