depends: `$(package)_*_env` settings only apply to the first command #22719

For example, $(package)_config_env is prepended to $(package)_config_cmds, which means that if $(package)_config_cmds contains multiple commands chained by &&, only the first command would have its environment modified according to $(package)_config_env.

https://github.com/bitcoin/bitcoin/blob/b935abb9eb2eeaceb5621e110e1889c2ce1b7734/depends/funcs.mk#L212

Since $(package)_*_env settings contain crucial env vars such as PATH or PKG_CONFIG_PATH, its omission in subsequent commands is likely a bug:

https://github.com/bitcoin/bitcoin/blob/b935abb9eb2eeaceb5621e110e1889c2ce1b7734/depends/funcs.mk#L137-L142

This has lead to problems such as: #16883 (comment)

A test-able demo of this problem: https://github.com/dongcarl/bitcoin/commit/e233c6d1e96ed35489c6be37f07bd01546083b9e

As export (see #19882) looks pretty invasive, maybe bash -c '...'?

As export (see #19882) looks pretty invasive, maybe bash -c '...'?

Wouldn't bash -c '...' have the same effect as export?

As export (see #19882) looks pretty invasive...

The assumption above is wrong.

As a new sub-shell is invoked for each line of the recipe, there are no side effects of using export (#19882).

A demo of the solution: https://github.com/hebasto/bitcoin/commit/926ba37cc5c351398253714fd143933d784dbc77.

Wouldn't bash -c '...' have the same effect as export?

Yes, it would.