`SIGPIPE` displayed during `make`/`make test`

[tersec]

For example, using -j4:

Building: build/nimbus_beacon_node
Building: build/deposit_contract
Building: build/resttest
Building: build/logtrace
SIGPIPE: Pipe closed.
SIGPIPE: Pipe closed.
Build completed successfully: build/logtrace
Building: build/ncli
Build completed successfully: build/resttest
Building: build/ncli_db
SIGPIPE: Pipe closed.
Build completed successfully: build/deposit_contract
Building: build/wss_sim
SIGPIPE: Pipe closed.
Build completed successfully: build/ncli
Building: build/stack_sizes
SIGPIPE: Pipe closed.

Where the signal mask is default:

$ env --list-signal-handling true
$ ./env.sh env --list-signal-handling true
$