Fix countIncludePaths test

This test was failing on lcgstack builds due to additional
include paths provided by the ROOT_INCLUDE_PATH environment variable.

These additional paths are now excluded when verifying the expected
count.

Author: LukasBreitwieser

roottest/root/meta/countIncludePaths.C

@@ -17,9 +17,14 @@ int countIncludePaths()
    // Exclude from the test the builds with R as external package
    if (std::string::npos != includePath.find("RInside/include")) return 0;
 
+   // count paths coming from the ROOT_INCLUDE_PATH environment variable
+   // and exclude them
+   std::string envVar(std::getenv("ROOT_INCLUDE_PATH"));
+   auto nEnvVarPaths = countSubstring(envVar, ":") + 1 - (envVar.back() == ':') - (envVar.front() == ':') ;
+
    // At most 10
    auto nPaths = countSubstring(includePath, "-I");
-   if (nPaths > 10){
+   if ((nPaths - nEnvVarPaths) > 10){
       std::cerr << "The number of include paths is too high (>9) " << nPaths
                 << ". The number of \"-I\"s has been counted in the include path of ROOT (gSystem->GetIncludePath()=" << includePath << ")." << std::endl;
       return nPaths;