Properly use MINA_BUILD_MAINNET flag

[dkijania]

Currently MINA_BUILD_MAINNET flag is set in export_git_env_vars.sh. However it's not exported and thus mainnet package is not built. This is due to lack of exporting MINA_BUILD_MAINNET flag which causes that build-artifact.sh script is not building mina_mainnet_signatures.exe which then is missing when trying to build debian. I think this was an effect of not complete merge to master since develop already has this change. I tested mix fix in nightly:

https://buildkite.com/o-1-labs-2/mina-end-to-end-nightlies/builds/2132

Jobs failing:

Build Mina for * - so basically all mina build jobs. For example:

https://buildkite.com/o-1-labs-2/mina-end-to-end-nightlies/builds/2130#01902914-0abe-470b-919e-5d67ac2004c0

[dkijania]

!ci-build-me

[dkijania]

!ci-nightly-me

[dkijania]

!ci-build-me

[dkijania]

Hello, @dkijania 1 new created to help you port this change to master. Please follow steps to resolve conflict for each mainline branch. PRs will be created automatically after you push merge to porting branches

develop

git fetch
git checkout merge/port_export_mainnet_build_on_master_to_develop
git merge export_mainnet_build_on_master
(Resolve conflict)
git push

[dkijania]

Porting branch #15760 to resolve conflict with develop created. Please merge it in order to solve conflict between head of this PR and develop

[georgeee]

@dkijania could you update PR with an information on why is this change necessary? AFAIU, some job is failing for master without this PR. Could you specify which?

[dkijania]

@georgeee updated

[dkijania]

!ci-build-me

[mrmr1993]

!approved-for-mainnet