The `make install` script, which most users would run via `sudo` to install into `/usr/local`, will use the current umask of the root user when creating certain files and directories. If one uses a restrictive umask by default (e.g. `umask 077`), this means that only the root user will be able to use the full Bitcoin package.

**Expected behavior**

The install script creates all directories and files, including man pages, etc., with permissions `644` / `755`.

**Actual behavior**

Certain folders are created using the default umask, e.g.:

- /usr/local/share/man/man1/
- /usr/local/lib/pkgconfig/
- [...]

This means that only root can access files in these folders and other users won't be able to read the man pages (for example).

**To reproduce**

```bash
$ ./autogen.sh
$ make
$ sudo -iu root
% umask 077
% make install
```

**System information**

OS: Linux
bitcoind version: HEAD
{
    for (const std::string& name : names) {
        AddArg(name, "", ArgsManager::ALLOW_ANY, OptionsCategory::HIDDEN);
    }
}
std::string ArgsManager::GetHelpMessage() const
{
    const bool show_debug = GetBoolArg("-help-debug", false);
    std::string usage;
    LOCK(cs_args);
    for (const auto& arg_map : m_available_args) {
        switch(arg_map.first) {
            case OptionsCategory::OPTIONS:
                usage += HelpMessageGroup("Options:");
                break;
            case OptionsCategory::CONNECTION:
                usage += HelpMessageGroup("Connection options:");
                break;
            case OptionsCategory::ZMQ:
                usage += HelpMessageGroup("ZeroMQ notification options:");
                break;
            case OptionsCategory::DEBUG_TEST:
                usage += HelpMessageGroup("Debugging/Testing options:");