With GCC 6.3.0 at least, if you try to compile a precompiled header witch include an another header that you have already precompiled, it don't use the precompiled one but the no precompiled. This give me two problems, one concern performance of course, second is about using method described in documentation when you building precompiled header in another directory adding a file with same name containing a #error message to be sure using precompiled header, in my case this give me an error. Thank you for the link, it confirms me that I need to create account on https://gcc.gnu.org/bugzilla/ Le dim. 3 juin 2018 à 23:32, Jonathan Wakely <jwakely.gcc@xxxxxxxxx> a écrit : > On 3 June 2018 at 20:19, François Leblanc wrote: > > Hi there, > > > > How or Where can I report g++ trouble with precompiled headers? > > What trouble? If you think it's a bug, then the same place you report > any g++ bugs > https://gcc.gnu.org/bugs/ >