Toolchain updates are breaking build versions that were built normally

[rockcavera]

I needed to build gcc 5.5.0. I have used your excellent script before with success in the past.

So, I cloned the repository and tried to do the build process and an error occurred, the same one reported here. I decided to investigate and created a patch for it. The problem passed, but new errors appeared, from possible incompatibilities of the previous gcc code with the toolchain using 12.2.0. I decided to use gcc 4.9.4 for construction and OK. The error was now building Python 3 with the old gcc. At this point I gave up on that approach in trying to fix bugs in devel.

I then looked for something that would indicate the last known successful build of gcc 5.5.0. I found commit f649dac. I regressed to it and built gcc 5.5.0 after correcting the links to expat and isl.

Well, I have proven with tests that changing the toolchain causes regressions in the build. Another regression that I assume has to do with this error was introduced in this commit 90a6683, but I didn't get to test it.

After saying all that, I believe the best way to control regressions would be to keep a file indicating the commit that each version was built correctly to facilitate the correction.

I verified that there is a choice of dependency versions according to the built version. This could be done with the toolchain as well.

[rockcavera]

Another question: how necessary is it to update the toolchain?

The little I know would be the last thing to update in a script like this, which intends to build several versions of gcc.

[niXman]

@rockcavera

hello!
im sorry for the delay.

thank you for your attention!

for the first post: you are right, that is a known trouble with mingw-builds projects. but I have no idea how to solve such troubles conveniently...
maybe you have some ideas?

Another question: how necessary is it to update the toolchain?

are you talking about a toolchain used as host compiler?

[rockcavera]

I don't have a suggestion. What could be done, at least for those who use it and want to investigate why a previous version broke, is to create a file in the repository, lastcommitbuilt.md for example, pointing to gcc vx.x.x and the hash of the last one commit which compiled correctly. It can be a starting point for a contribution with corrections in the model that the current script is, considering that script debugging can be very time consuming.

are you talking about a toolchain used as host compiler?

Yes, I'm talking about the host compiler, which is in "config-win.sh".