[MGPG-84] signing fails in eclipse when using gpg-agent

**[Piotr Morgwai Kotarbinski](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=JIRAUSER281931)** opened **[MGPG-84](https://issues.apache.org/jira/browse/MGPG-84?redirect=false)** and commented

after update from 1.6 to 3.0.1 signing started to fail when running maven from eclipse with the following message:

```
gpg: signing failed: No pinentry
```

When running from terminal, everything works ok.
Furthermore, after running from terminal, it also works ok in eclipse for about 1 minute. After about 1 minute it starts to fail again with the same error.

System info:
Apache Maven 3.8.3 (ff8e977a158738155dc465c6a97ffaf31982d739)
openjdk 11.0.11 2021-04-20
gpg (GnuPG) 2.2.4
Eclipse 2021-12 and 2021-03
ubuntu-18.04 amd64

```
$ echo $GPG_AGENT_INFO
/run/user/1000/gnupg/S.gpg-agent:0:1
```

---

**Affects:** 3.0.1

**Issue Links:**
- [MGPG-90](https://issues.apache.org/jira/browse/MGPG-90) Signing fails with 3.0.1: "no pinentry"

Start by reproducing Maven signing from Eclipse on Ubuntu with Maven 3.8.3, Java 11, GnuPG 2.2.4, and the reported GPG_AGENT_INFO value, then compare it with a terminal run. Done means signing remains successful in Eclipse beyond the reported one-minute window without the “No pinentry” error.

Written by the indexing model from the issue text.