diff --git a/nimterop/cimport.nim b/nimterop/cimport.nim
index d992c04..114ab80 100644
--- a/nimterop/cimport.nim
+++ b/nimterop/cimport.nim
@@ -82,18 +82,6 @@ proc getCacheValue(fullpaths: seq[string]): string =
     for fullpath in fullpaths:
       result &= getCacheValue(fullpath)
 
-proc getToastError(output: string): string =
-  # Filter out preprocessor errors
-  for line in output.splitLines():
-    if "fatal error:" in line.toLowerAscii:
-      if result.len == 0:
-        result = "\n\nFailed in preprocessing, check if `cIncludeDir()` is needed or compiler `mode` is correct (c/cpp)"
-      result &= "\n\nERROR:$1\n" % line.split("fatal error:")[1]
-
-  # Toast error
-  if result.Bl:
-    result = "\n\n" & output
-
 proc getNimCheckError(nimFile: string) =
   let
     (check, _) = execAction(
@@ -159,7 +147,7 @@ proc getToast(fullpaths: seq[string], recurse: bool = false, dynlib: string = ""
   when defined(Windows):
     result = result.replace(DirSep, '/')
 
-  if not fileExists(result) or compileOption("forceBuild"):
+  if not fileExists(result) or gStateCT.nocache or compileOption("forceBuild"):
     let
       dir = result.parentDir()
     if not dirExists(dir):
@@ -168,8 +156,8 @@ proc getToast(fullpaths: seq[string], recurse: bool = false, dynlib: string = ""
     cmd.add &" -o {result.sanitizePath}"
 
     var
-      (_, ret) = execAction(cmd, die = false)
-    doAssert ret == 0, getToastError(result.readFile())
+      (output, ret) = execAction(cmd, die = false)
+    doAssert ret == 0, result.readFile() & output
 
 macro cOverride*(body): untyped =
   ## When the wrapper code generated by nimterop is missing certain symbols or not
@@ -577,6 +565,8 @@ macro cImport*(filenames: static seq[string], recurse: static bool = false, dynl
   if gStateCT.debug:
     gecho nimFile.readFile()
 
+  gecho "# Saved to " & nimFile
+
   try:
     let
       nimFileNode = newStrLitNode(nimFile.changeFileExt(""))
@@ -673,7 +663,7 @@ macro c2nImport*(filename: static string, recurse: static bool = false, dynlib:
     nimFile = if nimFile.nBl: fixRelFile(nimFile) else: hFile.changeFileExt("nim")
     header = "header" & fullpath.splitFile().name.split(seps = {'-', '.'}).join()
 
-  if not fileExists(nimFile) or compileOption("forceBuild"):
+  if not fileExists(nimFile) or gStateCT.nocache or compileOption("forceBuild"):
     var
       cmd = when defined(Windows): "cmd /c " else: ""
     cmd &= &"c2nim {hFile} --header:{header}  --out:{nimFile.sanitizePath}"
@@ -699,6 +689,8 @@ macro c2nImport*(filename: static string, recurse: static bool = false, dynlib:
   if gStateCT.debug:
     gecho nimFile.readFile()
 
+  gecho "# Saved to " & nimFile
+
   try:
     let
       nimFileNode = newStrLitNode(nimFile.changeFileExt(""))
diff --git a/nimterop/toastlib/getters.nim b/nimterop/toastlib/getters.nim
index bfbd4be..df930bb 100644
--- a/nimterop/toastlib/getters.nim
+++ b/nimterop/toastlib/getters.nim
@@ -338,6 +338,10 @@ proc getPreprocessor*(gState: State, fullpath: string) =
                 start = true
                 newHeaders.incl line
                 break
+      elif ": fatal error:" in line:
+        doAssert false,
+          "\n\nFailed in preprocessing, check if `cIncludeDir()` is needed or compiler `mode` is correct (c/cpp)" &
+          "\n\nERROR:$1\n" % line.split(": fatal error:")[1]
       else:
         if start:
           if "#undef" in line:
@@ -345,6 +349,9 @@ proc getPreprocessor*(gState: State, fullpath: string) =
           gState.code.add line & "\n"
     elif not p.running(): break
   p.close()
+  assert p.peekExitCode() == 0,
+    gState.code & "\n\nFailed in preprocessing:\n  " &
+    getCompiler() & " " & args.join(" ")
   gState.headersProcessed.incl newHeaders
 
 # Plugin related
diff --git a/tests/include/tast2.h b/tests/include/tast2.h
index 06a0078..f9e0017 100644
--- a/tests/include/tast2.h
+++ b/tests/include/tast2.h
@@ -276,7 +276,7 @@ typedef union sx_ivec3 {
     struct {
         int x;
         int y;
-        struct z {
+        struct {
           int z;
         };
     };